Panzergranate 44 - German APFSDS

[schwarzpanzer]

tomo, sorry, but I've had to split my reply to you. I was 1,000 words over the limit. I managed to shorten it to just under 1,500 words, but it was very kurt txt spk! If this causes problems for the Mods/Admins, just let me know? Thanks.

Germans might have sticked with their Maybachs (if Russian engine was SO complicated ) and be done with that.

Yep, that is what I suggested. The engine was possible for mass-production (but the Germans couldnt make it in alu). But it had features that were only useful above 6,000rpm - good in an F1 car, not in a tank! The Maybach was much better, and bizarrely, simpler here (though the Soviet design was copied from an Italian design). Even then though, I'm not too sure if the 'Hemi-head' of the Maybach was all that necessary and desirable. IIRC/IMO a 'Bathtub' head design would be best (but I dont know Diesels that well).

Those two advantages would've allowe for a more compact vehicle, with better protection for same weight, or less weight for same armor protection.

True. The KV had a poor length-to-width ratio though, whereas the Tiger was almost square. Whether this would be a problem for a German copy though; I dont think so. Having a wider tank would increase the weight though, and a wider tank is necessary both for the length-width ratio and the turret ring diameter for that 88mm gun.

Again, we build this instead of Panther, not instead of Tiger.

Oh, right. Good point. Bear in mind though, that the top speed would only then be 25mph - the same as the other Panzers, maybe, but not enough to keep pace with a T-34 or Panther. Was top speed was an important, or silly criteria for the Panther design, do you think?

About the German decision or about advantages of diesel fuel?

Both, sorry.

The advantages do overweight disadvantages - from late 30's till now.
If you want so badly the frontal gearbox, than you might take in consideration the engine position too, and move the engine in front, Merkava-style.

It was a German obsession, but I can see both sides to the arguement. It did have advantages when the engine was moved forward though - as in the Geschutzewagen III/IV. A friend of mine had this design in a raccing car - but got a bit peeved when his competitors rammed him - breaking the connector rods, and leaving him unable to at least change gear! So it was a vulnerable design, though I have no sources to its breaking in combat directly available, I do remeber seeing one (in regards to the T-34, probably on Battlefield.ru). Also, changing gear in the T-34 and enturion I know was a knighmare. BTW Electronic Autos, IIRC Hydramatics do not have this problem... The Merkava design is a good one, but it puts the driver in a bad position - with a fore deign, there is a gap creted betweeen the input and output shafts that is just the ideal size for a seated person. Personally, I think the engine put in the centre, with a shorter torque tube and the drive inbetween them would be best - with the turret at the reaar. Torque tube lengths can cause knightmares though, however. As I said though, the Geschutzewagen III/IV seemed to have this feature ( wouldve made a cracking basis for a Katzchen-like APC IMO).

Both mechanically and by the weight.

Mechanically I have explained above (25mph 'only' - enough?). Weight is a difficult one...(though I will discuss this one elsewhere...).

The folks from Daimler Benz were influenced by a wrong Russian tank - they've should copied the KV...

The T-34 was a much better design IMO. Sloped armour, lighter and faster. The Panther managed to match the last point, but totally missed the 2nd one and only partly got the 1st. despite all this, it also managed to have thinner armour at the side rear!

One thing is needed to convert the field gun into AT gun - the will (or order, if you prefer) to do that.

Would it always work though?... BTW the British would not allow their 3.7in guns (Flak 88 euivalent) to be used for AT work - despite the lessons from Rommel. - This even when they had absolute air superiority!

You'd need to go to the tank-net.org to find out more - like I did

Drat! Thanks for the source. Can't you just tell me what you learned there?...

You're forgetting the 17pdr, plus 25pdr for SP arty...

You only said tanks, and I said excluding Lend-Lease. But I suppose you could count the Centurion, Bishop, Achilles, Avenger/Challenger (tanks??) Sentinel? I considered those, but deliberately left them out, as only 4 saw service and were considered SPGs, even though they had turrets - and one was Lend-Lease. Also, the Sentinel wasn't British. I suppose we can count the RAM too?

I was not reffering to the plethora of guns, but to (your) requirement that Cruisers should have carried almost all of those.

Not all at one time! Not on the same vehicle certainly. I think that at least 4 (or maybe all) would have been in simultaneous service - the 3 3.7in served together, the 2pdr 6pdr did, and the 75mm might have seen service with older variants. I seem to remeber the Matilda II (2pdr) being used in Europe though - so quite possibly! Of course, I would try to have just a few (only 2, if possible?...) and phase the older ones out.

New thread perhaps?

This was before you added 5 more to the list! (Czechs, Austrians, Hungarians, Poles and French). I think these will only be touched on here though? - unless you want to create a new Thread for these? May I suggest a title of 'Other Axis WW2 (HE/Support?) Artillery'?

Great post all BTW, as per!8)

 

[Shortround6]

BTW, I wonder if you might know: were APCBC rounds 1st intended for anti-ship useage?

Yes, and they were developed before WW I.

That's true, but I wasn't comparing WW2 HEAT to Cold War HEAT. I was just saying that CE (Chemical Energy) Attack is a viable way to destroy tanks - as it was British Doctrine in the Cold War ( is only being fased out now, reluctantly). It was also widely used by the Soviets in WW2, and to a lesser extent by the Germans and Americans. Annoyingly, Soviet projectiles often used KE shells to achieve CE-type destruction.lol:

This may be true but HEAT from rifled guns was a much less viable method in WWII. The poor performance of the HEAT shells meant that it was only used by guns that little, if any, hope of defeating armor by using KE. And if HE worked why did they go to the bother of developing the HEAT shells for these guns?
American 75mm pack howitzer, British 3.7in mountain howitzer, please note the British never fielded a HEAT round for the 25pdr.
If HE worked the way you seem to think why did the British issue the HEAT ammo in the far east, one would think that a 20lb HE shell would see off the Japanese tanks with their thin armor.

Thats a good, interesting point. The problem can also be that the projectile just passes right on through - only* creating a few holes, rather than ping-ponging around the interior, as is desirable (saved a Sherman and M10 on at least one occasion). Fuses can also stop penetration against thicker armour. Here is where I might suggest HE.

I am afraid the "ping-pong" theory doesn't hold up very well.
1. The Germans certainly didn't intend their AP ammo to ping-pong around the interior. they intended for it to penetrate and then blow up, causing many fragments to fly about in addition to the blast effect.
2. when penetrating thicker armor the metal that came out of the hole forms secondary projectile/s which fly about the interior at high speed.


on the 5.5in gun, it was in a book by Ian Hogg. it was British doctrine or procedure which may have never been used in combat. Please check the details of the heavy artillery, the 5.5in weighed over 6.5 tons and was not going to be gotten into or out of action quickly or easily and even tracking a moving target with a barrel that heavy could be a chore.

He has two very good books (actually he has more than I can count)

German Artillery of World War II

and

British American Artillery of World War II

which cover quote a bit of detail.

I would still think though, that most AFVs lost in WW2 were KO'd bt ATGs?

Artillery was the man killer. if it is forward deployed as AT guns it is not doing it's real job. Just like AA guns. Good, powerful AT guns but if forward deployed they are not tied into the the anti-aircraft net, they are not tied into their anti-aircraft directors and their fuse setters are useless, they are almost use less as AA guns except for firing shells into the sky for morale effect.

 

[Shortround6]

Would it always work though?... BTW the British would not allow their 3.7in guns (Flak 88 euivalent) to be used for AT work - despite the lessons from Rommel. - This even when they had absolute air superiority

This a common argument but again the reality was a little different.

some versions of the 3.7 had the trainer and aimer (two men, one for elevation and one for defection) facing backwards. not a problem as an AA gun when the two men used a follow the pointer system to aim/control the gun and never actually looked at the airplane/formation themselves. In other versions they did face forward. The weapon initially had no AT sight, so they would have had to be fitted in forward workshops after suitable telescopes were either shipped out from England or swiped from some other gun and cobbled into place. last the 3.7 was about hallf way in between the 88/56 and the 88/71 and weighed accordingly.

From Wiki, treat as you see fit;"

"This was mainly because the 3.7-inch (94 mm) gun mobile mounting was almost twice as heavy as the German "88". Redeploying it was a slower operation, and the heavy AEC Matador artillery tractor normally used for towing could operate on hard surfaces only. Additionally, heavy AA Regiments equipped with the 3.7-inch (94 mm) gun were controlled by Corps or Army HQ, or at even higher level HQs, and command of them was not often devolved to the commanders at Divisional levels where the anti-tank role might be required. Prolonged firing at low elevations (not part of the original specification) also strained the mounting and recuperating gear."

 

[schwarzpanzer]

Hi Shortround,

Thanks for the info on the power rammers.

I was thinking more for the towed artillery.

Though I woudnt know, Idve thought itd be the same for towed arty - maybe even moreso?

Thanks for the detailed info on HE. Though I wouldnt know, I would expect it would be the 1st option. tomo is really the one to ask? The first option would work on thin armour though, like that on the T-26 (also, the 2nd option proably would act like a normal AP round too - only witha bigger hole, also if an unstable shell filled with HE landed in the interior (assuming it didnt exit through the rear) - the crew would be outta there!). All I read was something like 'HE can cause spalling'.

I remember the A-20 (T-34 prototype) being labelled a 'shell-proof tank', but not the KV (thats not to say youre not right). The KV and T-34 were tested against AP fire from Soviet 76mm guns - a weird way of working, possibly (esp. as they had access to German designs), but one that proved fortuitous.

Not really for towed artillery. The idea of providing AP ammo was that these gun batteries would have some means of self defense should things go wrong and enemy tanks turn up where they were not expected.

I think the Flak 88 was always ready as a 'Super PaK' after the experience with them in the Spanish Civil War. The Soviet guns also had AT performance included in the design brief. These were always waiting for an excuse to put them in a vehicle, it seems. Of course though, AT work was only a secondary role - but the guns could (and later did) also function that way as a primary role - as often happened with Rommels 88s - much to the Luftwaffes annoyance!

Thanks for pointing out the difference between the PzIV, Stug StuHs roles vs regular arty. I tend to consider them just mobile platforms from them - ignorant, I know. I know they had less elevation though (?).

even the German army did not have the communications net early in the war that the US and British would later.

Do you have any more info on that? Sounds interesting.

I'm avoiding long-range arty fire. Just using them as an idea of having them as a basis for some super ATGs.

Of course, long-range arty fire could be used against tanks.

There were usages, and planned usages of the 380mm Sturmorser, and that Karlgerat-thingy against tanks, but I dont think we should go into that just yet? There was a funny quote from Rommel, IIRC on the Karlgerat.

Very true on digging weapons pits. Shall we agree that >105mm ATGs are impractical? Then again, the A-19 was OK - maybe the PaK 44 carriage was just badly designed? (it wasn't purpose-built, afterall). It was still OK though, just too heavy ( as you say, hard to dig in). In a bunker though... The flak 88 was still a dangerous opponent late-war, when dug in, it lost most of its vulnerability - also, IIRC, some had their gunshields removed or shortened?

At what point in the war? there was a lot of development in the 4-6 years of WW II. Some of the early Heat shells weren't that good.

I was thinking untill the 50mm L60 showed up, but even then... Early HEAT shells were the only things carried on German vehicles that could defeat Matildas (exepting those Flaktracks etc). Also, mentioning it, I think that during the Battle of France HE was used to KO a few heavily armoured French/British vehicles?

HEAT was also used later (in desperation though). BTW infighting between the German services led to the crews being held back in the early PzIVs (but not the StuGs, and Michael Wittman started his career here).

And trick ammo of the APFSDS isn't going to show up until 1944 at best and then it is doubtful.

hartman posted some info on the PPS APFSDS round right at the start of this Thread. Now I dont know, but it was developed for the 37mm PaK 36, so may have been a prototype for the later (?) rounds you seem to be alluding to? (PzGr 44) and thus available early war? (but possibly considered unecessary?). hartmann would be the guy to ask on this one.

You are talking about cherries and pumpkins

Penetration at 500meters using standard AP shot for both guns, 90 and 30 degrees, 50mm first. 78mm and 61mm. for the Lf 18 62mm and 56mm.
Same at 1000meters--50mm--61mm and 50mm----Lf 18----62mm and 52mm
pentration of Lf 18 at 1500meters 59mm and 49mm.
MV for Lf 18 using AP shell. 390M/sec. or about 4 seconds time of flight to 1500meters even disregarding wind resistance. Practical range is going to be close to 450meters.
With a MV of 823M/se the practical range of the 50mm (for getting hits) is going to be around 900meters. THe 50mm does have a much higher rate of fire, double if not a bit more and it weighs about 1/2 what the LF 18 does.
Niether one can really do the others job.

Yes I know. Thanks for the AP info. 450m? Yep, thats about where it started being effective with AP, IIRC.

At closer ranges, the 105mm will not suffer shatter, but the 50mm will/might(?). BTW did the LFH fire AP, APC, APCBC or APCR rounds? and did they have HE content? - always puzzled me, that one, perhaps now I'll finally find out! The shell I saw though, looked like blunt-nosed APC - so would seem to me to be less likely to bounce off the T-34s armour than the pointed 50mms? No idea if it had HE content or not, but IIRC it didn't - which would make shatter even less likely.

I know hits with HE would be hard past 1km?, but they would cause trouble for a T-34 - unlike with the PaK. Whilst KE is diminished with distance, CE isnt. How able would it be to hit a T-34 (moving @ 32mph) when firing HE, BTW? Even close hits can count.

Funnily enough, the main points when the PzIII got the 50mm L42 were that it could "Outrange the 2pdr, and fire a useful HE shell". Of course, that shouldnt be its raison d'etre - but this gun was mainly used for causing spalling when attacking British vehicles in NA, IIRC.

The Pak 38 is going to have trouble at even 1km given the slope on a T-34.

True.

The Lfh 18 is going to be in real trouble. The AP shell is about the same as the Pak 38's, a possible kill but no guarantee,

I was meaning with HE. AP would be in desperation. Though in the early stages of Barbarossa, one was brought up to destroy a problematic T-34 or KV. All t said was "105mm field gun", or something like (not flak though) - so I assumed it mustve meant the LFH18?

it takes until the 3rd or 4th try at a HEAT shell to get 100mm of penetration so heat shells aren't much good in 1941-42.

Do you mean the 3rd or 4th hit? I know it took about 4 attempts to score a hit with HEAT on early PzIVs (but that got better quickly). In the Battle of France, HEAT shells could destroy a Matilda, so a T-34 even KV shouldnt be too much trouble? They were initially meant for soft targets though IIRC - though AT performance was probably known? (AT rifle grenades of the time used this method).

given the low velocity of the 10.5cm round the high arching trajectory may require one or more sighting rounds to get the range.

Thats true. I tried it on a simulator, but found it hard (but thats probably more because I'm a crap artilleryman!). I may try again sometime, initially using HE this time...

As the range closes the performance of the Pak 38 improves a marked amount. The performance of the 10.5cm does not.

True, but the Pak will have troubles with skating and shatter - which the 105mm wouldnt (? - depending on the design of the round). I originally thought Why not have APCR for the LFH18?" but now I can see why that would be pointless (best use it in the Pak 38 - though APCR does load faster... At least I've moved on from the level of ignorance I had then!

Not sure what you mean by an indirect hit? a hit on a tool box or fender? and no, an indirect hit or near miss could not disable several T-34s, not unless they were unlucky enough to have shell fragments hit them directly in gunsight or periscope lenses. Shell fragments from an exploding shell are not going to make it through the armor from several meters away. The shock of the explosion will not cause spalling at that distance nor will it knock out running gear. Bend fenders and break headlights, yes and if you are really lucky it might give the crews a head ache or bloody nose or something.

I mean a near-miss, sorry - not plunging fire (but I suppose that too...). I meant it could jam or destroy the tracks, though other parts could be hit, like the sights you mentioned (or vent holes etc - which were exposed on the T-34, and often targeted - also on the French Char B btw).

I know shell fragments wont hurt armour plate otherwise (which is one of the reasons of what tanks were originally designed for).

The shock of the HE shell I went into above, and am not sure, but I expect it would cause spalling? - especially on the T-34, as Soviet armour was very brittle (but apparently less so on early T-34s, I can check). I am pretty sure that a hit on the running gear would disable the tank? Within what range?

Causing the crews problems is one. I remeber hearing stories of equipment falling on crews heads. Also, riveted vehicles were very vulnerable here - the T-34 KV werent riveted, but the T-26 was...

There was also a story of a KV that was hit repeatedly by a flak 88 (though penetration wasnt achieved) but the crew eventually gave up and ran. Some crews would even give up after the 1st hit. A similar tale to that of the KV is one from a British Matilda II - but that managed to retreat. That may not have been destroyed, but it seems as if it also couldnt continue.

Also, imagine the ringing in your ears - be like someone ringing an enormous gong!

 

[schwarzpanzer]

Hi Shortround (again!),

Thanks for the APCBC info. Before WW1?? Why?? 'Ironclads'?

This may be true but HEAT from rifled guns was a much less viable method in WWII. The poor performance of the HEAT shells meant that it was only used by guns that little, if any, hope of defeating armor by using KE.

True, rifling ruins HEAT performance. I wonder if the PPS round had sliding collars btw? and if it didn't, this would explain its rejection?... I think we'll have to wait till hartmann returns for an answer. Anyway, sliding collars would allow HEAT to work better? I wonder what the changes in HI/B and HI/C were? Were the KwK 37 and Italian 47 75mm guns rifled? Also there was the PaK 97/38:

7.5 cm Pak 97/38 - Wikipedia, the free encyclopedia

- wikipedia only, sorry.

And if HE worked why did they go to the bother of developing the HEAT shells for these guns?

To set them on fire! They developed HEAT shells for the 150mm SFH18 - but only the 'A' version (as far as I know). The 75mm KwK 37 got developed at least twice more to 'B' 'C' versions. Of course the Germans didnt see the IS-3 coming (which is the only vehicle the 150mm would be needed for (?)).

American 75mm pack howitzer, British 3.7in mountain howitzer, please note the British never fielded a HEAT round for the 25pdr.

All except the 25pdr had HEAT available? I suspect HEAT would be preferable with a less rifled barrel? IIRC all those also had AP shells available?

If HE worked the way you seem to think why did the British issue the HEAT ammo in the far east, one would think that a 20lb HE shell would see off the Japanese tanks with their thin armor.

The main problem in Japan was bunkers, which is probably what the HEAT were for. Grant tanks often had to resort to using AP shells to break up Japanese bunkers. Japanese tanks were the only ones vulnerable to the Boyes AT Rifle - PzIs maybe, or the side of others, but even the Sdkfz 251 was resistant.

Japanese tanks would be ideal targets IMO - they had rivets and required padding. Also, in hot environments HE might work better? Would humidity help, or hinder?

I am afraid the "ping-pong" theory doesn't hold up very well.
1. The Germans certainly didn't intend their AP ammo to ping-pong around the interior. they intended for it to penetrate and then blow up, causing many fragments to fly about in addition to the blast effect.

British AP was intended for this, and seemed to do OK.
1. True in theory, but often, when you hear of damage to Shermans etc, its when the fuse failed and the round bounced around - decapitating one poor bloke IIRC. When the round detonating upon hitting the armour, this was great news for the crew inside.

2. when penetrating thicker armor the metal that came out of the hole forms secondary projectile/s which fly about the interior at high speed.

Very good point - applicable to 'partial penetrations'?.

on the 5.5in gun, it was in a book by Ian Hogg. it was British doctrine or procedure which may have never been used in combat. Please check the details of the heavy artillery, the 5.5in weighed over 6.5 tons and was not going to be gotten into or out of action quickly or easily and even tracking a moving target with a barrel that heavy could be a chore.

Thanks, good info again!

He has two very good books (actually he has more than I can count)

German Artillery of World War II

and

British American Artillery of World War II

which cover quote a bit of detail.

I have the 1st one, but not the 2nd - heard it wasnt as good. With what you say, the fact that it covers 2 Nations though, I wil have to get it! Thanks!

Artillery was the man killer.

I dont suppose you have loss rates for both, or the source for that info? If not, I'll believe you anyway!

if it is forward deployed as AT guns it is not doing it's real job. Just like AA guns. Good, powerful AT guns but if forward deployed they are not tied into the the anti-aircraft net, they are not tied into their anti-aircraft directors and their fuse setters are useless,

It is argued by some (including me!) that the flak 88 was most useful as an ATG. Why not have fighters ( the Zerstorer concept) for attacking bombers?

they are almost use less as AA guns except for firing shells into the sky for morale effect.

Do you mean arty, or worn-out AA guns?

I often thought that the Blitz's Morale-booster guns wouldve been better served fighting the Panzers?...


Good points on the 3.7in, and the Wikipedia bit does seem OK to me (heard the thing about elevation from a few other sources IIRC). The 3.7in was used on occasion to fire at tanks though? Succesfully too IIRC? BTW the flak 88 did once fire at Tigers in a friendly fire incident - if it had been PaK 38s, this wouldnt have happened - suppose thats one disadvantage of the flak 88?

BTW The 1st part of that paragraph was me wondering if some field guns were totally unsuitable for AT use? I know the American 90mm AA couldnt use direct fire - but it did eventually morph into a tank killer. Also, the 76mm 3in ATGs were originally AA guns, which were in turn derived from field guns (or whatever!) IIRC.

 

[tomo pauk]

Hi tomo,
Because you hae no other choice? The IS-3 was not a lumbering beast like the German heavies, remember. Aiming for a mobility kill 1st is a good idea, however, but it may stil need finishing (or just blow the gun barrell off). You can't always rely on ambush? - sometimes head-to-head is the only option?... The IS-3 was apparently also good vs mines, as was also the KV (apart from mobility kills - which could be easily repaired - even then though, it might still be able to limp on?). As you said, air attack was not really an option for Germany in '44/'45 - and you make a good point about air attack also then being a threat, moreso than an IS-3? If you have heavy armour though, both might not kill you? - but will make life unliveable (the thing we've been discussing regarding CE, except from the opposite side).

I'll just say that there is more ways to skin a cat, but if the dog is you real problem, the cat slowly fades away

Ah, yes. I was deliberately stayig away from rockets/missiles though (that would be too much!). I suppose the PzH 2000 is very similar to the vehicles we are proposing? Also, I've seen wheeled 155mm SPGs.

Actually, the Pzh-2000 is some 10 times heavier than stuff I've described (made in Singapore); the French Caesar, or Israely, Yougoslavian German wheeled SPHs are really neat IMO.

OH NO!! Still, I'm sure you guys can help?

Anytime.

The ZiS-2? It was actually unpopular in 1941 early '42 though - not until the Tiger and Stug came on the scene did it gain much poularity - but even then, it had its detractors.

Not popular by whom?
The top brass didn't like it since it was expensive (yet they put it back into production in 1943 despite that), while it's best AP rounds (APCBC?) pierced Pz-III IV turrets through (both sides!).

The KwK could be considered Dual-Role though, the ZiS-2 not so much.

The difference is like Tiger's vs. Panther's guns.

Still, why the 85, 100 even 122mm's AP performance wasnt made to be more like the 57mms totally escapes me.

Yep, I guess they should have produced something better of AP kind.

I suppose HE can disable an Abrams - but has CE directly destroyed one?? The Merkava was blown up by something like a 650kg IED IIRC - impossible to be fired from a field cannon? A Merkava has apparently been destroyed, frontally, by an RPG-29 - which counts, but I mentioned that type of weapon. Any info on those Abrams would be appreciated! 8)

I'll have to point you to the tank-net.org again for more specific info

Yes, but thats only the 'container' (like it is in a HE shell). If you stripped the Chobham off a Challenger, you'd end up with something that resembled a Cheiftain - which is the 2nd, 'steel' layer I mentioned. Deletig the stell on the outer part may allow for more 'shock' on an incoming projectile though?...

I'd venture to say that 'container' has only limited armor value, but more of structural strength.

There was apparantly a KV with IIRC, a 107mm gun - 'The Beast of Leningrad'. Whether it was an actual KV-13 (?) (which was cancelled), or a lash-up, I don't know (or if it was a myth/propaganda). Apparently though, it did see action - so info will be somewhere? However, like the KV-2, it would've had too many limitations.

Not that many limitations - the turret was more akin in size to KV-85, than of KV-2.

A 107mm on an SU-152 chassis though...

Nasty surprise in Kursk
The 122 would've been nice to have back then too.

The IS-2 also hadan 85mm gun. I like the 100mm much better than the 122mm, though it may be true that the 122mm was more available. I think the 122mm was the main reason that stopped the IS-2 being an effective Heavy or Breakthrough tank.

The IS with 85mm was IS-1, IIRC.
I'm not sure that IS-2 'stoped to be an effective H. or BrTh. Tank' was true for WW2.

 

[tomo pauk]

True. The KV had a poor length-to-width ratio though, whereas the Tiger was almost square. Whether this would be a problem for a German copy though; I dont think so. Having a wider tank would increase the weight though, and a wider tank is necessary both for the length-width ratio and the turret ring diameter for that 88mm gun.

While I may agree that Tiger's L/W ratio was good, KV's wasn't that poor either.
Just how much the turret ring size one needs for 8,8cm??? If the Russkies managed to mount the 85mm, plus a 5th crew member in turret of their T-34s, why the Germans woudl've needed more for their 8,8cm. Atop of that, 85mm was not equipped with muzzle brake, and therefore recoiled a great deal.

Oh, right. Good point. Bear in mind though, that the top speed would only then be 25mph - the same as the other Panzers, maybe, but not enough to keep pace with a T-34 or Panther. Was top speed was an important, or silly criteria for the Panther design, do you think?

I don't think 25mph would've been too slow; there is no Panthers in our time line, and just perhaps 100 of T-34s beyond 1942 in Wehrmacht anyway
Since they governed down the original speed of Panther, I'd say it was not worth the trouble.

Both, sorry.

For German decisions, I'd like to point you to Christian Ankestjerne (www.panzerworld.net); think he was mentioned that in a forum we're the members.
We could have another thread about diesel vs. gasoline, but the price/availability the lower flammability are the main ones.

It was a German obsession, but I can see both sides to the arguement. It did have advantages when the engine was moved forward though - as in the Geschutzewagen III/IV. A friend of mine had this design in a raccing car - but got a bit peeved when his competitors rammed him - breaking the connector rods, and leaving him unable to at least change gear! So it was a vulnerable design, though I have no sources to its breaking in combat directly available, I do remeber seeing one (in regards to the T-34, probably on Battlefield.ru). Also, changing gear in the T-34 and enturion I know was a knighmare.

The T-34 had problems with type of transmission, not with the layout of same. The clutch operation of 30-ton vehicle was/is not that easy anway.

BTW Electronic Autos, IIRC Hydramatics do not have this problem...

Exactly.
(Electric, not electronic...)

The T-34 was a much better design IMO. Sloped armour, lighter and faster. The Panther managed to match the last point, but totally missed the 2nd one and only partly got the 1st. despite all this, it also managed to have thinner armour at the side rear!

While T-34 featured sloped armor (but not really more sloped vs. KV-1), the horizontal thickness was lower, making 5cmL60 a viable weapon.
You can lump 'lighter' 'faster' together - it was faster since it was lighter. KV-1s, rendered that almost completely, BTW.
OTOH, KV-1 always have had 3rd crew member in the turret, and always featured a radio set. It also featured more modern suspension.

The main T-34's advantage was it's lower price.

Would it always work though?... BTW the British would not allow their 3.7in guns (Flak 88 euivalent) to be used for AT work - despite the lessons from Rommel. - This even when they had absolute air superiority!

3,7in was not a field gun
While 8,8cm was widely added to various formations, plus it was there by day one, the 3,7in was more likely to be seen in the UK, rather than in Egypt, main task being protection of Suez Canal locks IIRC - away from front line.
By the time Monty was in hot pursuit (and even before of that), UK army already have had plethora of other artillery more than able to dispose with any Pz-III/IV in direct-fire sights.

Drat! Thanks for the source. Can't you just tell me what you learned there?...

It all comes to hitting the tank with WP shell, which ignites on impact, engulfs enemy tank with fire... Not very nice.

You only said tanks, and I said excluding Lend-Lease.

17pdr was mounted in British tank (Challenger)...

This was before you added 5 more to the list! (Czechs, Austrians, Hungarians, Poles and French). I think these will only be touched on here though? - unless you want to create a new Thread for these? May I suggest a title of 'Other Axis WW2 (HE/Support?) Artillery'?

Nice title, but it would've to wait till September - my working season started last week, so I have scarce time

 

[Shortround6]

Thanks for the detailed info on HE. Though I wouldnt know, I would expect it would be the 1st option. tomo is really the one to ask? The first option would work on thin armour though, like that on the T-26 (also, the 2nd option proably would act like a normal AP round too - only witha bigger hole, also if an unstable shell filled with HE landed in the interior (assuming it didnt exit through the rear) - the crew would be outta there!). All I read was something like 'HE can cause spalling '.

with the HE breaking up-rupturing on impact the amount of armor it could penetrate in relation to the size of the shell was rather limited. Naval guns often had several classes of shells from HE to AP, some sort of semi-AP that was rated at a percentage of it's diameter. Full HE wasn't considered useful for piercing any thickness of ship armor (which to be fair, was usually a minimum of 1-2 in.) 'HE can cause spalling' is not the same as WILL cause spalling, you can win at a casino too

Thanks for pointing out the difference between the PzIV, Stug StuHs roles vs regular arty. I tend to consider them just mobile platforms from them - ignorant, I know. I know they had less elevation though (?).

Platforms are more like the Wespe and the various SP 15cm inf gun carriers. They provided mobility way better than a truck but were not meant for direct combat.

Do you have any more info on that? Sounds interesting.

It is a subject in itself but basically in the beginning of the war a single artilley observer controlled a single battery of artillery or perhaps a 3 battery group. And most often with telephone wire. German use of radio instead was an advance. But one observer could not talk to other batteries and and even artillery battalion Qs could not talk to each other. By the end of the war a Single British observer, should he get permission could call on every gun within range of the target, no matter what unit it really belonged to. Like neighboring divisions, corp artillery, etc. but not necessarily AA units which weren't part of the net although they could be used in planned fire mission. This took many more radios and operators and also miles of wire and operators.

There were usages, and planned usages of the 380mm Sturmorser, and that Karlgerat-thingy against tanks, but I dont think we should go into that just yet? There was a funny quote from Rommel, IIRC on the Karlgerat.

There was also a case where a Churchill ARVE took out a Tiger tank with it's Petard mortar. Tiger was hiding inside a multi-story building on the ground floor and the Petard bomb collapsed the building on the Tiger. The other ARVEs certainly didn't plan to go Tiger hunting based on that.

I was thinking untill the 50mm L60 showed up, but even then... Early HEAT shells were the only things carried on German vehicles that could defeat Matildas (exepting those Flaktracks etc). Also, mentioning it, I think that during the Battle of France HE was used to KO a few heavily armoured French/British vehicles?

Yes it was, and it worked so well that both sides started a desperate search for something better to use.
The first 75mm shell for the MK IV was rated at 70mm of penetration. Works better than a 37mm but no guarantee on a Matilda. The Second HEAT shell for the 105 is rated at 80mm penetration. Again how much over penetration is needed for a fair chance of a kill?

hartman posted some info on the PPS APFSDS round right at the start of this Thread. Now I dont know, but it was developed for the 37mm PaK 36, so may have been a prototype for the later (?) rounds you seem to be alluding to? (PzGr 44) and thus available early war? (but possibly considered unecessary?). hartmann would be the guy to ask on this one.

The last numbers in the year usually signify the year of adoption or design, but not always. So PzGr 44 ammo should have been designed or adopted in 1944. Unless somebody has something that says otherwise.

At closer ranges, the 105mm will not suffer shatter, but the 50mm will/might(?). BTW did the LFH fire AP, APC, APCBC or APCR rounds? and did they have HE content? - always puzzled me, that one, perhaps now I'll finally find out! The shell I saw though, looked like blunt-nosed APC - so would seem to me to be less likely to bounce off the T-34s armour than the pointed 50mms? No idea if it had HE content or not, but IIRC it didn't - which would make shatter even less likely.

It might have been APHE, it wasn't moving fast to worry about shatter and a cap wouldn't have done much good. It didn't generate enough velocity to make APCR worthwhile either. The second AP Design carried 400 grams of HE. You are confusing shattering with shell breakup or rupture. Shatter is when the nose of the projectile hits armor too fast for the steel/alloy to take the stress and nose (point) of the projectile breaks up leaving a blunt rough shape to try to bull it's way through. Shell break up is when the body of the shell can't take the stress of impact and slits open. Given the 1.34kg HE capacity of the standard HE shell I think we can ssume the size of the cavity in the shells was in proportion so the AP shell has a hollow space of about a 1/3 the one in the HE shell.

I know hits with HE would be hard past 1km?, but they would cause trouble for a T-34 - unlike with the PaK. Whilst KE is diminished with distance, CE isnt. How able would it be to hit a T-34 (moving @ 32mph) when firing HE, BTW? Even close hits can count.

A tank doing 20mph is moving at 29-30ft a second and the howitzer has a time of flight to 1000meters in excess of 2 1/2 seconds. Tank can move 75 ft while shell is in the air. guess wrong on the speed by 5mph and you miss by about 20ft. guess wrong on range by even 50 meters and you probably miss.

Funnily enough, the main points when the PzIII got the 50mm L42 were that it could "Outrange the 2pdr, and fire a useful HE shell". Of course, that shouldnt be its raison d'etre - but this gun was mainly used for causing spalling when attacking British vehicles in NA, IIRC.

main reason for introducing the 50mm L42 was that it could penetrate at 1000meters what the 37mm could at 100meters and at 500 meters what the 37mm couldn't at any range. At At 1000meters it could out penetrate the 37mm using AP40 at 500meters. I would tend to doubt the spalling story, unless you think that potato masher hand grenades can cause spalling. The 50mm L42 did have a useful HE shell. If it was the same as the 50mm L60 it contained 165gms of HE which might 6 1/2 times what the 37MM HE carried. While not ideal or maybe even what was desired it worked a whole lot better at suppressing dug in British 2pdr anti-tank guns, troops in fox holes/slit trenches or troops in buildings than the 37m HE ammo or just MG fire.

I was meaning with HE. AP would be in desperation. Though in the early stages of Barbarossa, one was brought up to destroy a problematic T-34 or KV. All t said was "105mm field gun", or something like (not flak though) - so I assumed it mustve meant the LFH18?

HE would have been desperation also. HE will break tracks or damage running gear, blow road wheels off, thus immobilizing tanks.

Do you mean the 3rd or 4th hit? I know it took about 4 attempts to score a hit with HEAT on early PzIVs (but that got better quickly). In the Battle of France, HEAT shells could destroy a Matilda, so a T-34 even KV shouldnt be too much trouble? They were initially meant for soft targets though IIRC - though AT performance was probably known? (AT rifle grenades of the time used this method).

Nope, I mean the 3rd or 4th design of shell. 1st design wasn't very good and few were issued, 2nd design of 10.5cm shell was good for 80mm of penetration according to one source. British were the first to feild a rifle grenade: No. 68 AT Grenade - Wikipedia, the free encyclopedia


More later.

 

[schwarzpanzer]

Hi tomo,

I'll just say that there is more ways to skin a cat, but if the dog is you real problem, the cat slowly fades away

Took the words right outta my mouth. That IS-3 still needs dealing with though...Air-Defense is another story though? - tanks can't be expected to deal with aircraft?...

Once again, thanks for the help/offers.

Not popular by whom?
The top brass didn't like it since it was expensive (yet they put it back into production in 1943 despite that), while it's best AP rounds (APCBC?) pierced Pz-III IV turrets through (both sides!).

It was actually pretty cheap - its carriage was used to reduce the cost of the ZiS-3. Its main 'problem' was that it wasnt so good at firing HE. Piercing turrets through both sides was one of the real problems - while it sounds cool, it is actually less effective. Its 'best' AP rounds were HVAP (debatable) (APCR - BR-271P BR-271N), though APCBC was available (BR-271 BR-271M - dunno if /HE) as was APHE (BR-271K) and AP (BR-271SP). This is why I'm surprised APHE wasnt dropped on the bigger guns - APCBC had much better performance. Then again, apparently the D-10 used Naval ammunition, so that may explain why?

However, once thicker-armoured vehicles came on the scene, overpenetration was no-longer a problem, and production resumed.

The difference is like Tiger's vs. Panther's guns.

True, though the Panther still fired a reasonable HE shell (75mm being considered the minimum, though IIRC it had a thick casing - thus inferior performance). Thats given me an idea...

Looks like I'll have to go to tanknet? - but I'd feel such a traitor!

I'd venture to say that 'container' has only limited armor value, but more of structural strength.

Nah, it just holds it in place. Like the skin on a banana.

Not that many limitations - the turret was more akin in size to KV-85, than of KV-2.

Is that the KV-13? 'The Beast of Leningrad' had a KV-2-alike turret.

Nasty surprise in Kursk
The 122 would've been nice to have back then too.

True. The 122 was available - as the A-19 and in the SU-122 - the SU-152 wasnt exactly poor...(maybe even better than the 122mm).

The IS with 85mm was IS-1, IIRC.
I'm not sure that IS-2 'stoped to be an effective H. or BrTh. Tank' was true for WW2.

There were 2 IS-1s(or more) and 2 IS-2s (or more). The difference was in armament, a few Soviet sources always say IS-85, IS-100 etc - which is probably the best way to go about things. I say 'more' in brackets, because some IS-2s were 'upgraded' with 122ms ( annoyingly then became IS-2s!). This version is the 1st IS-2, the '44 Model is the 2nd, then I say 'more' because there was then the 'proper' IS-2M. Simple, eh?

The IS-2 was, IMO, not an effective Breakthrough tank because: 1. Its turret front/mantet armour was too thin ( brittle) - making going hull-down futile and 2. Its gun coldnt engage at acceptable ranges, the D-10 would have been far better IMO ( still able to deal with bunkers?). I think the old saying "Stalin turned into Hitler" is true here (but in a bad way).

While I may agree that Tiger's L/W ratio was good, KV's wasn't that poor either.

It was considered problematic though (albeit > the preceding SMKs).

Just how much the turret ring size one needs for 8,8cm???

Not all 80+mms are born equal. The KwK 36 may have only had 3mm more in diameter, but had a much bigger shell IIRC. Add to this the much better propellant and you have much more recoil - requiring a larger turret ring - unless you copy the KV-2s 'teapot turret'.

If the Russkies managed to mount the 85mm, plus a 5th crew member in turret of their T-34s, why the Germans woudl've needed more for their 8,8cm.

In addition to the above, Germans were bigger than Russians though - which always caused problems. Besides, the Tiger was designed with the SS in mind - who had a minimum recruitment height of 6ft. One of the requirements for being a Soviet T-55 tank driver was apparently a height of no more than 5Ft 4in. When Israelis captured T-55s, they didn't like them because they were cramped - despite being otherwise being mostly superior to the Centurions.

Atop of that, 85mm was not equipped with muzzle brake, and therefore recoiled a great deal.

The muzzle brake was deleted from the L70 gun in the Panther Ausf Fs Schmallturm though...(still trying to work that one out!).

I don't think 25mph would've been too slow; there is no Panthers in our time line, and just perhaps 100 of T-34s beyond 1942 in Wehrmacht anyway
Since they governed down the original speed of Panther, I'd say it was not worth the trouble.

There are T-34s though... For what role is the design for? I dont think they gverned the speed of the Panther below 30mph? - and the Jagdpanther could do 32mph IIRC, probably because of the sturdier trans. IIC thogh, it was only engine revs that were governed?

Thanks for the link.
Perhaps another Thread on Gas vs Diesel?

The T-34 had problems with type of transmission, not with the layout of same. The clutch operation of 30-ton vehicle was/is not that easy anway.

Both, basically, the designs go like this:

Aft: Engine in middle, trans @ rear, driver in front. Trans requires connector links, rods cables that are thin can snap and always require adjusment. Also, they often go through the engine bay, so are subjected to heat stress (especially if they are made of plastic! lol).

Fore: Engine @ rear, trans driver in front. Torque tube connects trans to driver, is basically a thick, solid rod of steel -so no problemos). In addition to this, the torque-tube (basically a surrounding metal pipe) protects it. However it is prone to going out of balance and needs careful manufacture. It also allows storage space in between it the hull sides. It allows the heavy engine to go at the back, helping with cG. The main benefit is, inlike with afts, the gearstick can go straight into the gerabox - giving easy, positive shifts. The gearknob breaking off is probably your main worry here! I think also, that German transmissions were also Clutchless Preselectors? - though transmissions arent my strongpoint.

Exactly.
(Electric, not electronic...)

I thought I said Electric? Like I said, not my stongpoint. Were Electric Autos ever used in WW2? Funnily enough, though Hydrmatic is considered the most reiable transmission type now, it wasn't in WW2 tanks (M6 Pershing). Infac, it was the M6s biggest flaw! Also, bizarrely Spur gears were thought to be the Panthers Achilles heel - though I think this is wrong, have been researching it.

While T-34 featured sloped armor (but not really more sloped vs. KV-1), the horizontal thickness was lower, making 5cmL60 a viable weapon.
You can lump 'lighter' 'faster' together - it was faster since it was lighter. KV-1s, rendered that almost completely, BTW.
OTOH, KV-1 always have had 3rd crew member in the turret, and always featured a radio set. It also featured more modern suspension.

The T-34 was a more modern design. Now whilst I dont like it when people equate 'modern' with 'better' in this case, it is true. The armour was much more sloped than the KV ( Panther). 60 degress is the magic angle - any less isnt as much use, 60 degrees should always be aimed for. The T34 still had vertcal lower side armour though - making it vulnerable there.

The Pz III was much lighter than the Panther, yet much slower...

Thanks for the info. It had torsion bars (according to some sources), yes, but it had differnt roadwheels (which had to be upgraded for the KV-1S IS-2). Still, I think it had its advantages. This warrants further discussion...

3,7in was not a field gun

I know. Shouldve put 'AA' in there?

While 8,8cm was widely added to various formations, plus it was there by day one, the 3,7in was more likely to be seen in the UK, rather than in Egypt, main task being protection of Suez Canal locks IIRC - away from front line.

I think this was not such a smart idea? Still, lots of 3.7ins were available, but werent used. Some were used before this though - proved to be brilliant. I think the 32pdr (well, something like it!) should have come online a lot earlier.

By the time Monty was in hot pursuit (and even before of that), UK army already have had plethora of other artillery more than able to dispose with any Pz-III/IV in direct-fire sights.

I suppose once the 17pdr came online, it was less use - but the 17pdr wasnt available in massive numbers.

It all comes to hitting the tank with WP shell, which ignites on impact, engulfs enemy tank with fire... Not very nice.

Like a flamethrower/Molotov? Thought as much (but wanted to be sure). Weird I've never heard of it before. When did it see service?

17pdr was mounted in British tank (Challenger)...

The Challenger has always been considered an SPG by my sources (except Wikipedia), but OK, I'll give you that one!

Nice title, but it would've to wait till September - my working season started last week, so I have scarce time

Thanks. OK. I'm OK till next month (if I'm not in Hospital).

 

[Shortround6]

True, but the Pak will have troubles with skating and shatter - which the 105mm wouldnt?

Skating?

The second type of AP round for the Pak 38 used a capped projectile which should go a long way in solving the shatter problem.

I am pretty sure that a hit on the running gear would disable the tank? Within what range?

since blowing parts out of the running gear is with in the capabilities of HE ammunition (given the shell has enough HE content to begin with) the range comes down to at what range can you get an acceptable number of hits? If you have enough ammo to accept 1 immobilized tank for every 20-25 rounds expended then you have a longer range than if you need to immobilize 1 tank for every 8-10 rounds expended.

Thanks for the APCBC info. Before WW1?? Why?? 'Ironclads'?

they had given up on ironclads by about 1890. In fact compound armor predates that by a few years, compund armor being a thin (ship thin=several inches) steel plate either bolted or "welded" to iron backing plates. The welding being done by pouring molten iron ito the space between the two plates. By 1895 Nickel steel was in use and face hardened "carburized armor was being made in several places by 1900.
As gun velocity's went from under 2000fps to almost 3000fps the projectile makers had to improve their products.

Anyway, sliding collars would allow HEAT to work better? I wonder what the changes in HI/B and HI/C were? Were the KwK 37 and Italian 47 75mm guns rifled? Also there was the PaK 97/38:

The Germans were working on sliding collars for HEAT shells but never got them into production despite Hitler ordering 40,000. All the guns mentioned were rifled. It is one reason their HEAT shells did so poorly. See the 8cm PAW 600 for the difference. 140mm of penetration for an 8cm projectile. This by the way is the ONLY smoothbore cannon made in any numbers at all in WW II. Please note that for practical purposes these German HEAT rounds from rifled guns were good for penetration of about their own diameter. The best seems to be the "C" version shell for the KwK 37 which is credited with 100mm or 1.33 times it diameter. American shells didn't do any better 91mm penetration for the 75mm howitzer shell and 102mm for the 105 howitzer HEAT shell. I can't find the figures for the British 3.7 mountain howitzer but it can't have been good. It was noted as being short in length in order to fit into an standard pack mule ammo carrier ans so had a less than optimum stand off distance.
Also please note than many of the guns used less velocity on the HEAT shells than they did on the heavier HE rounds. To high an impact speed degrades HEAT performance, at least in the WW II era.

on the "ping pong theory" Just what target thickness or range are these projectiles designed for?
If you shoot at the front of an enemy tank and penetrate the frontal armor of the hull the round is going to zip through and hit the engine bulkhead/firewall which is probably not armor but mild steel and just thick enough for structural support and to keep engine compartment fire in the engine compartment. It is not going to take much excess penetrating power for the round to zip right on through and into the engine compartment. Once tanks started using thinner armor on the side than they did the front things get real complicated. Round that goes through front at an angle and bounces of the side (avoiding firewall) is going to have enough power to zip right through both sides. No "ping pong" effect there. If projectile just penetrates enemy tank at 1000yds and "ping pongs"does that mean that the round is failure at 250-500yds where it may have enough power to make it out the other side/rear?
While projectiles did ping pong around on occasion can anybody find any specifications or design requirements that would suggest that the projectiles were DESIGNED to do it?

It is argued by some (including me!) that the flak 88 was most useful as an ATG. Why not have fighters ( the Zerstorer concept) for attacking bombers?

What happens when the enemy manages to avoid the fighters? or the enemy has better fighters than you do to escort his bombers?

Do you mean arty, or worn-out AA guns?

No, I mean AA guns that are in front line AT positions, disconnected from their fire control equipment or having some of their AA equipment stripped off. An 88 when used as an AA gun was firing with 10-20 seconds of flight time. The target bomber (or formation) flying at 240mph could move a mile or more while the shell was in flight after leaving the barrel. without range and height finding equipment, fire control computers (called predictors) and fuse setters receiving up to the moment data from from the predictor, even a new AA gun was little more than a moral booster for it's own side and perhaps a morale dropper for the enemy. Then you also have the problem that any gun (artillery piece) within a few miles of the front line that fires at anything is going to be "spotted", even by sound, and it's location (even approximate) marked down for counter battery fire.

 

[Shortround6]

This is why I'm surprised APHE wasnt dropped on the bigger guns - APCBC had much better performance. Then again, apparently the D-10 used Naval ammunition, so that may explain why?

It depends on the size of the burster. A 10-20gram buster isn't going to take up enough volume to make much difference and many APCBC had HE burstes, peaple just didn't want to type the extra letters
In US service sometimes APC was actually APCBC. If there was no actual APC round in that caliber but there were pllain AP and APCBC the BC was dropped.

However, once thicker-armoured vehicles came on the scene, overpenetration was no-longer a problem, and production resumed.

There were also the problems of factory relocation, ammo production and even perhaps barrel production (that long barrel needed different machinery than the 76.2 barrel) , Russians were heavily into standardizing just a few weapons in the winter of 1941 as long as they worked. By 1943 not only did the Germans have thicker tank armor but Russian production problems had eased up and alternative designs could be considered for production.

True, though the Panther still fired a reasonable HE shell (75mm being considered the minimum, though IIRC it had a thick casing - thus inferior performance). Thats given me an idea...

Some anti-tank guns used a reduced charge for the HE round with lower velocity. This allows for thinner shell walls/more HE and less barrel wear. It does require extra marks in the gun sight and extra training.

True. The 122 was available - as the A-19 and in the SU-122 - the SU-152 wasnt exactly poor...(maybe even better than the 122mm).

Depends on the job=less armor penetration, less range, less ammo capacity within the confines of an AFV.
More HE and perhaps better penetration of earth and concrete.

Not all 80+mms are born equal. The KwK 36 may have only had 3mm more in diameter, but had a much bigger shell IIRC. Add to this the much better propellant and you have much more recoil - requiring a larger turret ring - unless you copy the KV-2s 'teapot turret'.

Recoil is proportional to shell weight X velocity + propellent weight X velocity of escaping gas which is usually figured as a constant.

When Israelis captured T-55s, they didn't like them because they were cramped - despite being otherwise being mostly superior to the Centurions.

Please, more jokes

I think also, that German transmissions were also Clutchless Preselectors? - though transmissions arent my strongpoint.

Early Russian T-34 transmissions had problems, stories of T-34s going into combat with spare transmission tied to engine deck with steel cables and preventing full rotation of the turret. Standard equipment for KV-1 driver was a large hammer to 'assist' in gear shifting. Also stories about KV- drivers just picking one gear and getting tank rolling and sticking with it, not up shifting to hit top speed.

It was not an easy thing to design a transmission that could handle 500hp in 1939-40 and just like the German tanks, installing it in heavy tanks just adds to the strain. Transmissions were often part of the steering gear, but not so much on Russian tanks.
Russian tanks used what is called "Clutch and Brake". Drive line is laid out like a short "T" with the engine on the vertical part and the drive sprockets on the arms. Engine clutch is between engine and transmission. A right angle gear set changes direction of the drive after the transmission. On each arm there is a steering clutch and a brake. Gentile turns are done by slipping or disengaging the clutch on the inside of the turn. Sharper turns are done by disengaging the clutch and applying the inside brake. While this works OK on light vehicles it becomes increasingly unsatisfactory the heavier a vehicle gets. Long road marches on straight level roads aren't to bad but lots of twists and turns can eat up steering clutches as well as brakes. Going down hill can be a lot of fun too. If the engine isn't pulling (vehicle is 'coasting') de-clutching one track will cause the tank to swing in the opposite direction. Non-syncro transmissions are a bunch of laughs too. If you miss the shift from 3rd to 4th (or vice versa) you often have to bring the vehicle to a complete stop and start over. Missing the shift means you are stuck in neutral.

Pre-selector transmissions had clutches, think of them as sort of a combination automatic gear box and clutch. Driver used transmission control to select the gear he wanted and when he activated the clutch control the transmission shifted itself. They were more expensive to manufacture and might require more adjustment in the field but they were easier to drive and, with driver less likely to make mistakes, clutches and the gears themselves lasted longer.

M-5 light tanks and M-24s also used hydromatic transmissions. Again more expensive and in need of more minor maintenance but less likely to suffer catastrophic failure in day to day use.

The Pz III was much lighter than the Panther, yet much slower...

19.5-23 tons/265-300hp compared to 43-45.5 tons and 650-700hp?

Panther had about a 14% power to weight advantage. And an extra gear in the transmission.

 

[tomo pauk]

Hi tomo,

It was actually pretty cheap - its carriage was used to reduce the cost of the ZiS-3. Its main 'problem' was that it wasnt so good at firing HE. Piercing turrets through both sides was one of the real problems - while it sounds cool, it is actually less effective. Its 'best' AP rounds were HVAP (debatable) (APCR - BR-271P BR-271N), though APCBC was available (BR-271 BR-271M - dunno if /HE) as was APHE (BR-271K) and AP (BR-271SP). This is why I'm surprised APHE wasnt dropped on the bigger guns - APCBC had much better performance. Then again, apparently the D-10 used Naval ammunition, so that may explain why?

However, once thicker-armoured vehicles came on the scene, overpenetration was no-longer a problem, and production resumed.

The other main shortcoming of 57mm was the increased barrel wear (and it was more expensive - hence only 750 pcs prior the production was stopped) because it fired projectiles at huge speed (for 1941). Since the 76,2mm cannon (the USV model) offered better HE performance, while still very much able to blow the panzers, Russkies decided to drop 57mm and produce the long 45mm (L66), at half price of 57mm.

For 100mm, I'll have to check it before answering.

Looks like I'll have to go to tanknet? - but I'd feel such a traitor!

I don't have problems reading Serbian forums sites, while my country ( me) was in was with them 15 years ago.

Is that the KV-13? 'The Beast of Leningrad' had a KV-2-alike turret.

You can take a look at this drawing, with turret almost half of height of KV-2's turret:
KV-1 (107mm gun)

There were 2 IS-1s(or more) and 2 IS-2s (or more). The difference was in armament, a few Soviet sources always say IS-85, IS-100 etc - which is probably the best way to go about things. I say 'more' in brackets, because some IS-2s were 'upgraded' with 122ms ( annoyingly then became IS-2s!). This version is the 1st IS-2, the '44 Model is the 2nd, then I say 'more' because there was then the 'proper' IS-2M. Simple, eh?

My take would be, production versions:
-one version of IS-1 (85mm)
-two versions of IS-2 (the second version featured glacis plate of constant slope, not cranked)

The IS-2 was, IMO, not an effective Breakthrough tank because: 1. Its turret front/mantet armour was too thin ( brittle) - making going hull-down futile and 2. Its gun coldnt engage at acceptable ranges, the D-10 would have been far better IMO ( still able to deal with bunkers?). I think the old saying "Stalin turned into Hitler" is true here (but in a bad way).

It was good, but not ideal IMO

It was considered problematic though (albeit > the preceding SMKs).

That's vague point...

Not all 80+mms are born equal. The KwK 36 may have only had 3mm more in diameter, but had a much bigger shell IIRC. Add to this the much better propellant and you have much more recoil - requiring a larger turret ring - unless you copy the KV-2s 'teapot turret'.

Quick google search yields this (for HE shells):
8,8cmL56 (Flak): 9,4kg @ 820m/s =6320 kJ (momentum 7710 kgms = recoil force)
85mm M1939 AA: 9,2kg @ 790m/s = 5740 kJ (momentum 7268 kgms)
Hardly that advantageous (under 12 7% respectively), despite all the praise for 8,8.
With muzzle brake that reduces recoil some 25-30%, 8,8cm KwK should've recoil far less - perhaps the Russkies have done better job converting AA piece to AFV use?

In addition to the above, Germans were bigger than Russians though - which always caused problems. Besides, the Tiger was designed with the SS in mind - who had a minimum recruitment height of 6ft. One of the requirements for being a Soviet T-55 tank driver was apparently a height of no more than 5Ft 4in.

Hmm, the arrogance tends to backfire...

When Israelis captured T-55s, they didn't like them because they were cramped - despite being otherwise being mostly superior to the Centurions.

Not superior; perhaps even, and that only until Centurion received 105mm.

There are T-34s though... For what role is the design for?

Manin battle tank - MBT?

I dont think they gverned the speed of the Panther below 30mph? - and the Jagdpanther could do 32mph IIRC, probably because of the sturdier trans. IIC thogh, it was only engine revs that were governed?

Shove the Maybach on 'our' KV-88/Panther and you have 30 mph pronto

Perhaps another Thread on Gas vs Diesel?

Okay

Both, basically, the designs go like this:

Aft: Engine in middle, trans @ rear, driver in front. Trans requires connector links, rods cables that are thin can snap and always require adjusment. Also, they often go through the engine bay, so are subjected to heat stress (especially if they are made of plastic! lol).

Fore: Engine @ rear, trans driver in front. Torque tube connects trans to driver, is basically a thick, solid rod of steel -so no problemos). In addition to this, the torque-tube (basically a surrounding metal pipe) protects it. However it is prone to going out of balance and needs careful manufacture. It also allows storage space in between it the hull sides. It allows the heavy engine to go at the back, helping with cG. The main benefit is, inlike with afts, the gearstick can go straight into the gerabox - giving easy, positive shifts. The gearknob breaking off is probably your main worry here! I think also, that German transmissions were also Clutchless Preselectors? - though transmissions arent my strongpoint.

That's theory (even if I find some points debatable).
Practice says all-aft layout was better - and it dominated the tank world for some 60-70 years.

The T-34 was a more modern design. Now whilst I dont like it when people equate 'modern' with 'better' in this case, it is true. The armour was much more sloped than the KV ( Panther). 60 degress is the magic angle - any less isnt as much use, 60 degrees should always be aimed for. The T34 still had vertcal lower side armour though - making it vulnerable there.

By what accounts it was 'more modern'? The 60 degs are hardly magic, with 30 I'll agree...
You can read the Russian accounts when they've tested Pz-III(E?) and T-34 - Pz-III was faster (almost 70 km/h), with 5 crew members vs. 4 of T-34, better ergonomics radio of Pz-III...
Of course, T-34 have had better gun, much better protection off-road performance.

The Pz III was much lighter than the Panther, yet much slower...

See above

Thanks for the info. It had torsion bars (according to some sources), yes, but it had differnt roadwheels (which had to be upgraded for the KV-1S IS-2). Still, I think it had its advantages. This warrants further discussion..

.

Yep, torsion bars for KV. The road wheels were replaced with ones with bigger radius.

I think this was not such a smart idea? Still, lots of 3.7ins were available, but werent used. Some were used before this though - proved to be brilliant. I think the 32pdr (well, something like it!) should have come online a lot earlier.

Too bad the Brits haven't found the way to convert pre-war 3in AA piece for AFV use in greater numbers; that one would've lay waste in N. Africa.
OTOH, Commonwealth forces suffered mostly in time Axis forces were equipped with Pz-II Italian tinclads, proving (again) that there is no remedy for bad tactic strategy (save the numeric advantage).

Like a flamethrower/Molotov? Thought as much (but wanted to be sure). Weird I've never heard of it before. When did it see service?

Think from Normandy on

 

[schwarzpanzer]

Hi Shortround,

Sorry I have left Emoticons off of my replies to you, please don't mistake this and think I'm being curt.

This is also the 1st of a 3-part reply.

Thanks for the info on HE again. Thick, malleable armour will make spalling much less likely however – and stop the shockwaves.

I suppose there are 2 types of HE 'Penetration'?:

1. The armour is blown apart. Partial penetrations can probably occur here too. Welds can be shredded, as can the actual armour plate itself.

2. Spalling is caused, crew or equipment are damaged etc.

HE was used against tanks in WW2. I will give the Soviet examples: Early war, HE was the only shell carried by the KV-2 , and was used successfully to destroy Wehrmahcht vehicles (light armour). Apparently too, the T-34 was only available with a few HE shells initially, due to Kuliks meddling – so HE may have been what was used here too? Late War, the IS-2s HE shell was capable of causing spalling on the German tanks thick, but poor quality armour (according to battlefield ru).

HE was used by Tigers to destroy M10s and the sides of earlier 'Dry' Shermans – even having advantages here, vs the normal PzGr 39 AP round. American armour was apparently the most malleable of all the WW2 combatants though, so against thick US armour, this often wouldn't work – only on the brittle armour of the German Soviet tanks, and the riveted/bolted armour of many British ones. However, I suspect HE could still tear the many joins on Composite US tanks apart.

On an aside, HE shells could destroy the thin roofs of tanks – using plunging fire. This is out of my scope though, but it might be nice to cover it here?…

All armour penetrating is a % chance, these figures are not correct, just an example for a 100mm plate @ 1,000m – from 0.1% chance of a 37mm AP round, to a 99.9% chance for an 128mm.

Sometimes, you just have to use what you've got available.

Platforms are more like the Wespe and the various SP 15cm inf gun carriers. They provided mobility way better than a truck but were not meant for direct combat.

Thanks for the info, but I have difficulty understanding these subjects. I did get that though, thanks to your explanation. I think perhaps, that we should start a WW2 Support SPGs thread?…


Thanks for the Arty Observer info.

There was also a case where a Churchill ARVE took out a Tiger tank with it's Petard mortar. Tiger was hiding inside a multi-story building on the ground floor and the Petard bomb collapsed the building on the Tiger. The other ARVEs certainly didn't plan to go Tiger hunting based on that.

That's interesting. That's a different thing though – though I have often wondered what would happen if a 'Flying Dustbin' were to hit a Tiger?…

The 1st example I gave was where a large, low-velocity, demolition HE shell, mounted on an SPG has directly destroyed vehicles, due to the blast. The Karlgerat was only discussed though, admittedly – its AT ability, that is.

A torpedo also destroyed a Panzer in WW2. I would guess with HE? Torpex?

Yes it was, and it worked so well that both sides started a desperate search for something better to use.
The first 75mm shell for the MK IV was rated at 70mm of penetration. Works better than a 37mm but no guarantee on a Matilda. The Second HEAT shell for the 105 is rated at 80mm penetration. Again how much over penetration is needed for a fair chance of a kill?

Of course, it wasn't ideal. Why do you say "both sides"? Anyway, one of the measures taken was to develop the HEAT shell! 80mm isn't exactly great against a Matilda II (78-80mm), but it is better than the 65mm of the 37mm like you said, and even the 69mm of the very rare 50mm KwK 38 L42 - both of those are even at 100m, @ 90 degrees - which is not likely to happen. APCR figures are 79mm for the 37mm (theoretically 1mm over – but in practicality not enough) 115mm for the 50mm L42 – but that is @ 100m 90 degrees. The same source gives 90mm of penetration for the Gr38 '/A' HEAT round though (that's not much different to yours though). Also, HEAT would comfortably deal with the Matilda I – whereas nothing else could?

Also, even if penetration isn't achieved, I suspect a series of holes from HEAT rounds would weaken the armour more than 37mm AP shells just bouncing off?

The last numbers in the year usually signify the year of adoption or design, but not always. So PzGr 44 ammo should have been designed or adopted in 1944. Unless somebody has something that says otherwise.

I wasn't talking about PzGr 44, sorry. The round hartmann posted was it's predecessor, called PPS, IIRC. It is possible that this round was developed in the '30s – but not taken further because the PzGr 39 37mm was deemed adequate at that time. When more info comes through from hartmann, then we'll know more.

PzGr 44 was possibly only issued in 1945, maybe, maybe '44 - and even then in small numbers and never seeing combat. Even its mere existence is hotly debated and denied by many. Even if it did see service, I don't really see the use in it (in the guns it was used for), but I think its basic design had advantages for other guns.

It might have been APHE, it wasn't moving fast to worry about shatter

Good point!

and a cap wouldn't have done much good.

It would have helped against the sloping armour, and oblique impact angles though. The one I've seen seems more like the 'blunted' type - more suitable for sloped armour.

It didn't generate enough velocity to make APCR worthwhile either.

But isn't the whole point of APCR a higher muzzle velocity? - at the expense of a rapid drop in velocity. Whether it could fire a cartridge that would be enough for a decent APCR round is possibly the question?… Thanks for the info though, it's making me start to see why APCR might not be so hot for this weapon.

You are confusing shattering with shell breakup or rupture.

No, I'm not. But the two are interlinked? I think pretty much if one happens, then the other likely will too? Except on shot, of course! – even then though, the projectile itself can fragment, rather than just be 'blunted'. Sorry if I confuse the conversation with linking the two though – I tend to say 'shatter' for both. Apparently, another advantage of Uranium projectiles is that they are 'self-sharpening'.

With both though, penetration can still apparently be achieved – but I wouldn't bank on it!


Thanks for the info on it being able to hit a moving target (or not). Still, getting even near it with HE might disable it – allowing for a well-timed direct hit? I'm gonna have to dig that Sim out again, and see if I can do it. If I can train myself to do it though (albeit in peacetime) then anyone can?

main reason for introducing the 50mm L42 was that it could penetrate at 1000meters what the 37mm could at 100meters and at 500 meters what the 37mm couldn't at any range. At At 1000meters it could out penetrate the 37mm using AP40 at 500meters. I would tend to doubt the spalling story,

True, but it would still not be able to defeat Matildas, or do any better than the 37mm vs Cruisers – apart from outranging the 2pdr. This means that it could probably destroy Cruisers at ranges the 37mm couldn't, true, but couldn't destroy Matildas, by penetration… I will need more long-range data though IIRC the 37mm's performance @ normal combat ranges vs Cruisers was not much different?…

unless you think that potato masher hand grenades can cause spalling.

Funny you should mention that!: There was a device called the Geballte Ladung – which was another desperate measure, intended for destroying tanks. Penetration figures are given as 20mm, but some sources go as far as 60mm! It was apparently intended to fight T-34s though – so the latter figure might not be so silly?…

Thanks for the info on 50mm HE shells, vs 37mm MGs. I would even go so far as to suspect that it was also better than the KwK 37 for direct HE fire against ATGs? – especially mounted as it was on the better performing, more stable, heavily armoured PzIII. How would you rate the PzII here, btw?

HE would have been desperation also. HE will break tracks or damage running gear, blow road wheels off, thus immobilizing tanks.

I meant that HE rounds had more 'reach'. AP only being effective to < 500m. Disabling is probably the best you're gonna get with guns carried on fully-tracked vehicles? (except for spalling). That is excepting even trickier moves with lighter guns - such as shooting up the gun barrel, in radiator grills etc. Of course, such guns as the 37mm can use AP to destroy tracks, but are less effective than 105mm shells for this purpose (though a hit is easier). Then again though, a direct hit with a 105mm shell is probably not needed (?) – a near mss should do it?

Nope, I mean the 3rd or 4th design of shell. 1st design wasn't very good and few were issued,

The fact that it was developed shows it had usefulness to me.

2nd design of 10.5cm shell was good for 80mm of penetration according to one source.

Are you sure that means 105mm, not 75mm?

British were the first to feild a rifle grenade:

Yes, I remember that. IIRC great penetration, but hard to use? Also, on the subject of Brit infantry AT devices, there was the 'Sticky Bomb' – which IIRC used HE to directly destroy armour? Then that Home Guard recoilless rifle-thing (forget the name).

 

[schwarzpanzer]

Hi Shortround (Part 2!),

Skating?

Yes, bouncing off at oblique angles.

The second type of AP round for the Pak 38 used a capped projectile which should go a long way in solving the shatter problem.

Which round is that? Apparently, all Pak 38 AP ammo was capped.

Shatter can still happen when 'undermatching' happens. The much larger diameter of the 105mm, combined with its low velocity, would greatly reduce the chance of this happening, when compared to the PaK 38.

since blowing parts out of the running gear is with in the capabilities of HE ammunition (given the shell has enough HE content to begin with) the range comes down to at what range can you get an acceptable number of hits?

That's the question. Allsorts of factors to consider (target speed etc). I don't think 'hits' is necessary? – near misses being enough perhaps? The fact that this is so complicated to me leads me to believe it would be impractical, but I'm no arty expert – I wonder what tomo thinks?… To disable a tank may require a whole battery – but an immobilised one can be destroyed by a single LFH 18, IMO. A single gun vs a moving target though?…

If you have enough ammo to accept 1 immobilized tank for every 20-25 rounds expended then you have a longer range than if you need to immobilize 1 tank for every 8-10 rounds expended.

I don't get that, but I assume you mean if you have shells to throw away? I would expect that HE shells are cheaper than the specialised alloys, construction and propellants of APs? Also, captured stocks can be used.


Thanks for the Ship armour info. That is Composite Armour though to me (like Chobham). Which is unfair to compare to (most) WW2 tank armour. I expect the iron backing plates were brittle though? – but the join I would expect to negate this?

As gun velocity's went from under 2000fps to almost 3000fps the projectile makers had to improve their products.

Now that is very relevant. Exactly the velocities encountered here. Still, whilst HE content is necessary (?) – yet at the same time, undesirable, for Naval use, I think it is both undesirable and more to the point, unnecessary, for AT use.


Thanks for the Sliding Collars info. Also, thanks fro reminding me about the PAW. I think though, that the Puppchen did even better?

Please note that for practical purposes these German HEAT rounds from rifled guns were good for penetration of about their own diameter.

That's a good one, thanks. This would mean though that a HEAT shell for the FH 18 would easily be able to deal with the T-34 KV? – also, HEAT could have a higher MV than either AP or HE – and thus a longer range, and direct-fire AT ability?

The C shell would probably be enough to deal with any WW2 threat then, saving the IS? (though even then…) Some were actually used after Normandy! (IIRC in penal battalions). By this point though, I would agree that the 75mm L24 was long obsolete (?).

The American British shells were enough, for what they were (not designated ATGs). The 105mm apparently was the best thing at Kasserine pass – being the only thing really capable of destroying Tigers, frontally. The failures of the 3in M1 are less easy to forgive though…

The British pack howitzer would've been enough for bunkers? A Boyes AT Rifle would be enough for Japanese tanks otherwise.

Also please note than many of the guns used less velocity on the HEAT shells than they did on the heavier HE rounds. To high an impact speed degrades HEAT performance, at least in the WW II era.

Doesn't it also degrade HE performance though? I suppose this destroys my idea of using the LFH 18 for direct-fire – but, many HEAT rounds were used for direct-fire. I think though, that HEAT would only be useful above 500m, so should be 'charged' appropriately – leaving anything closer to a 'super-charged' APC round. A similar problem was encountered with the D-10T – which used myriad of different rounds for differing ranges (HEAT being for long-range).

on the "ping pong theory" Just what target thickness or range are these projectiles designed for?

You would need to look at the 2pdr's design brief (, later, the 6, 17, 32pdr's) – though IIIRC it was 30mm @ 1,000 yds. I wonder if this was carried on to the 20pdr after? I expect so (never really went away!).

If you shoot at the front of an enemy tank and penetrate the frontal armor of the hull the round is going to zip through and hit the engine bulkhead/firewall which is probably not armor but mild steel and just thick enough for structural support and to keep engine compartment fire in the engine compartment. It is not going to take much excess penetrating power for the round to zip right on through and into the engine compartment.

That would still be bad. The thing is though, that after penetration, the round would likely 'tumble' and not hit @ 90 degrees. It could also hit something other than the firewall. It would behave like a pool ball really. Some German armour actually exploited this 'tumbling'. Sorry tomo, I know you use 'tumbling' to refer to something else ('skating/bouncing' in my lingo!).

Once tanks started using thinner armor on the side than they did the front things get real complicated. Round that goes through front at an angle and bounces of the side (avoiding firewall) is going to have enough power to zip right through both sides. No "ping pong" effect there.

That's true, but if it isn't too powerful for the target (like the ZiS-2 vs PzIII, mentioned previously) it will likely be deflected. The probability of this? Well…?

If projectile just penetrates enemy tank at 1000yds and "ping pongs"does that mean that the round is failure at 250-500yds where it may have enough power to make it out the other side/rear?

1,000 yds is the average combat range. Below that you have allsorts of problems, such as shatter. The best bet is to not let it get that close. If it gets to below 1,000yds, you're probably dead anyway. The C/BC may slow down the round enough @ close range – also, the caps will have deformed – reducing secondary penetration levels. If it does make it out the other side, or into the rear compartment - then I think it will have destroyed the vehicle! (?)

While projectiles did ping pong around on occasion can anybody find any specifications or design requirements that would suggest that the projectiles were DESIGNED to do it?

This was the 1st, last method used/intended. The 1st being the WW1 7.92mm 'K bullet', the last being Tungsten Rods HESH. Of course, the 1st 2 would also factor in incandescence… German, Soviet APCR would also factor I here – as would the supposed fragments from the AP/HE. Like I wrote above too, all WW2 ( post-war) British AP Shot was intended for this purpose (along with a possible secondary incendiary effect).

When it accidentally happened on AP/HE rounds, this is to me when it was probably most effective. That is, of course excepting the 'through--through' incidents that you mentioned (which did happen).

What happens when the enemy manages to avoid the fighters? or the enemy has better fighters than you do to escort his bombers?

True, though I think there you concentrate on more/better fighters, at the expense of Strategic Bombing. This was Rommels plan, and to me, it makes sense (though his layers of PaKs idea has since been holed, air superiority would bring it back into contention).


Thanks for the AA Fire Control info.

I suppose using Flaks for AT work would wear out the barrels for AA work. IMO though, using them for AA work would wastefully wear the barrels for AT work. Do you think frontline 88mm AA guns were a waste of time? (excepting for AT work).

 

[schwarzpanzer]

Hi Shortround (Part 3),

It depends on the size of the burster. A 10-20gram buster isn't going to take up enough volume to make much difference and many APCBC had HE burstes, peaple just didn't want to type the extra letters

True, but I think the 100mm round had too much HE content. I think it's pointless anyway – if it was only 10-20gms, what would be the point? The British designers came to the same conclusion – it just adds manufacturing costs, time complexity, whilst reducing performance - after-penetration effects are adequate with shot anyway? APHE wasn't used on British ATGs, except maybe a few initial 2pdr test rounds.

In US service sometimes APC was actually APCBC. If there was no actual APC round in that caliber but there were pllain AP and APCBC the BC was dropped.

Now that is plain confusing! I have seen some test results from Kubinka on the US 76mm that are ambiguous, but now I'm not so surprised!

The rounds were named like 'M79' etc, and were very confusing anyway. There is a story that goes with them... All types were used in WW2: AP, APC APCBC (all with /HE). I have seen what seemed to be APCBC described as APC – now I know why, thanks!


Good additional points on the ZiS-2. It actually helped production of the 76.2mm in the short-term though – it's carriage being more suitable for mass-production ( lighter) found it's way onto the ZiS-3. The initial 76.2mm had a longer barrel though, which I would have kept (there were 3+ variants).

Some anti-tank guns used a reduced charge for the HE round with lower velocity. This allows for thinner shell walls/more HE and less barrel wear. It does require extra marks in the gun sight and extra training

.

That's a good point. I wonder if the KwK 42 had this feature? – and the KwK 40?…

That's got me thinking – a myriad of different rounds, requires more marks on the sights. For a KT, these might be for: AP, HE, APCR APFSDS - those last 2 being totally pointless? Also, that US 76mm mentioned above. I think the max amount of shell types carried should be 3? (excepting Smoke Canister). I suppose Arty HE fire doesn't depend on sights so much though? – rather plotting corrections from an observer?

Depends on the job=less armor penetration, less range, less ammo capacity within the confines of an AFV.

- a lower rate of fire?

I thought the 152mm had more penetration?

Recoil is proportional to shell weight X velocity + propellent weight X velocity of escaping gas which is usually figured as a constant.

I forgot to add – the KwK 36s cartridge was bottle-necked. I did have figures kicking around till recently on the Brit 17pdr gun vs the US M1A1 – although both are 76.2mm, there is a lot of difference in the levels of propellant.


Hey, that wasn't a joke!


Thanks for the extra info on the Soviet transmissions. I've heard the T-34 story before, but didn't know it stopped turret rotation.

Yes, the Soviets had much more powerful, heavier tanks, yet their transmissions seemed to lag behind? Transmissions are key to any tank design IMO (or any ither design, for that matter) – I think that should be sorted 1st.

I am just old enough to remember non-synchro, but not why it was bad (missed shifts IIRC, as you said). I think synchro reduces transmission strength though – IIRC Dog-Engagemet is stronger, but harder to use ( in a tank, you want ease of operation – but strength too…).

Thanks for the preselector info. That's nice and easy. The Hetzer was preselector, so was the Pz38t? Any more? I think that, in this case, more complex German engineering is a good point. How strong is the basic preselector design? Is Synchromesh necessary on it?

Thanks for the info on US Light Tank Hydromatics. They're the most reliable kind now. I don't like the M5 Chaffees drivetrain though (the twin engines – not the trans). I heard though, that early Hydromatic fluid was very flammable?

19.5-23 tons/265-300hp compared to 43-45.5 tons and 650-700hp?

True, allsorts of things affect top speed. Power being but one of them. Power/weight ratio is not necessarily the thing that affects top speed (but I think we can discount aerodynamics?! lol).

Panther had about a 14% power to weight advantage. And an extra gear in the transmission.

Ah, but early PzIIIs had 10 gears – 4 more than the Panthers… ( the KT had 1 more, but was also slower). It's main point was probably the large roadwheels (givin a larger rolling radius) – combined with longer-legged gearing (larger roadwheels up the gearing also).

 

[Shortround6]

Sorry I have left Emoticons off of my replies to you, please don't mistake this and think I'm being curt.

No worries

I suppose there are 2 types of HE 'Penetration'?:

1. The armour is blown apart. Partial penetrations can probably occur here too. Welds can be shredded, as can the actual armour plate itself.

2. Spalling is caused, crew or equipment are damaged etc.

If you detonate enough explosive close to a vehicle you get an over pressure condition. A blast wave (not shock wave) hits the vehicle. this may be hundreds of pounds per sq in or in extreme cases over a thousand lb/sq in. This can destroy the structure and bend plates. Think hurricane winds or tornado only worse. Or think about houses blown apart by a gas explosion. entire walls blown out on the ground. But think about it. even 5 psi might be enough to destroy the the house if it is applied to the entire wall. 5 psi times 144 sq in per sq ft, times 8 feet high and 12 feet long=69,120lbs of force or just over 34 tons. for a single room wall.

True spalling is caused by setting up shock waves in the material itself. this requires setting up energy waves (think sound waves, as in a sonic boom) in the material itself. These waves are of such intensity that pieces of metal are thrown off at high speed on the opposite side the force was applied on.

This is what HESH does. High explosive squash head. A special shell (thin walled with a net of some sort to contain the explosive, keep it from splashing out too far) with a base fuse that is designed to detonate the special explosive ( a hard brittle explosive wouldn't work) after it has gone from a column in the shell to a plate sized "patty" smeared onto the armor. a similar amount of explosive, still in cylinder form with one end facing the armor and detonating even a fraction of an inch away is hardly going to have the same effect.
If you use a big enough shell and detonate it close enough you may get spalling effect. True the thickness and quality of the armor will have some effect but how thick was the armor of the T-34 prototype that was supposed to "shell proof" against 75-77mm shells?

The 1st example I gave was where a large, low-velocity, demolition HE shell, mounted on an SPG has directly destroyed vehicles, due to the blast. The Karlgerat was only discussed though, admittedly – its AT ability, that is.

I am sure that by searching hard enough you can come up with freak happenings for a lot of weapons. Most of the discussions may be post war by war gamers of the "Timmy, the power gamer" type. I am not sure you could even fire Karl-Gerat at zero degrees elevation. Loading rates, traverse, and low velocity mean these would be short range, limited, one shot wonders at best. And just when does the rocket on the 380mm Stormtiger kick in? after it has left the muzzle? does wonders for accuracy. doesn't matter against large building or group of trucks or at 200-300 yds but for a long range weapon?

Of course, it wasn't ideal. Why do you say "both sides"? )........ Also, HEAT would comfortably deal with the Matilda I – whereas nothing else could?

I say both sides because both the Germans/Italians/ Japanese? and the Allies were looking at HEAT or shaped charges from before the start of the war. Pretty much means nobody was happy with HE against tanks.

You might want to check on that "comfortably deal with" also. There seemed to be more variation in round to round performance of shaped charge shells than KE projectiles. And you have to figure the angle of impact. for instance a HEAT shell impacting a 60 mm plate at 45 degrees actually has to make a hole through 84.4 mm of material, it doesn't magically align itself for a 90 degree penetration. It doesn't have the skid or ricochet problem that KE projectiles do though

The round hartmann posted was it's predecessor, called PPS, IIRC. It is possible that this round was developed in the '30s –

There was a bit of work going on about super long range shells for artillery or for getting an AA shell to altitude quicker. But that was to get an HE payload to the target, not a KE projectile which might present some different problems even if you do have the shape right.

But isn't the whole point of APCR a higher muzzle velocity? - at the expense of a rapid drop in velocity. Whether it could fire a cartridge that would be enough for a decent APCR round is possibly the question?… Thanks for the info though, it's making me start to see why APCR might not be so hot for this weapon.

The AT and Tank guns that used APDS got about a 30-40% increase in penetration and had to pay the price of Tungsten carbide use for that. Maybe you can fire a standard 75mm APCBC projectile out of a 105 barrel by using sabots but is it going to be any faster/better than a normal 75mm AT gun? And you have the bigger size/weight of the 105.

No, I'm not. But the two are interlinked? .

I think you are.
Armor penetration depends on a lot of factors and the actual mechanics/process changes with the metallurgy and impact speeds ( and who you listen to).
Going back to the iron clads it was found that a hard plate could cause a cast Iron ball/shot to shatter on impact. Chilling the cast shot as it cooled made it harder and better able to penetrate and the hardness race was on, except that too hard meant brittle and the plates could crack right across or the shot broke up. for englongated projectiles they tried chilling just the nose or using a difeerent heat treat on the nose than on the body so the body would remain a bit softer but tougher (bend a bit before breaking). It was found that a bit of point worked better than a flat nose (or ball shaped nose). It stressed a local point on the armor and weakened it and tended to push material aside rather than trying to shear out a plug like a high speed flat faced punch. At higher impact speeds some of the dynamics change. But maintaining the point was found to be critical to best performance. At certain speeds (around 2000fps ?) it was found that the heat treated points of the projectiles began to shatter on impact and minor changes to heat treatment and/or alloys didn't solve the problem. This is the start of the "piercing cap" a cap of a softer but tougher material was placed on the front. on impact it spread the load to the shoulders of the projectile and protected the nose. As it deformed it pre-stressed the armor target and even acted a bit like a lubricant as the intact hard nose of the projectile went through it's own cap penetrated the armor plate.
An HE shell body breaking up under the stress of impact and spilling it's load isn't really the same thing.

Funny you should mention that!: There was a device called the Geballte Ladung – which was another desperate measure, intended for destroying tanks. Penetration figures are given as 20mm, but some sources go as far as 60mm! It was apparently intended to fight T-34s though – so the latter figure might not be so silly?…

that device has 42 oz of TNT or explosive in it. or almost 1.2 kg. How much in a 105 shell?
Some accounts speak of trying to throw/place the charge on the engine deck/grates which are hardly 60mm thick.

Then again though, a direct hit with a 105mm shell is probably not needed (?) – a near mss should do it?

a mighty near miss. I think a 150-155 had to land under 10 yds away to have reasonable chance of disabling a tank and the 105s carried 25-33% of the explosive of a 150-155mm?

The fact that it was developed shows it had usefulness to me.

Well, you have to start somewhere and a look at the drawings shows why it wasn't very good. In 1938-1940 a lot of people knew the general principal which dated back to before 1900. It was turning this laboratory trick into a usable weapon that took a few years. The fact it wasn't issued in numbers and that the version which replaced it was only marginally better than the AP shot indicates the first version wasn't very good.

Are you sure that means 105mm, not 75mm?

Not according to one source.

Yes, I remember that. IIRC great penetration, but hard to use?.

Lousy penetration. about 2 in or 50mm and you needed a 90 degree impact angle to get that. Once you got through the 30mm armor of a MK III or IV with an angled impact did it really have much more effect inside the tank than an anti-tank rifle bullet

 

[Shortround6]

(Part 2!),
Which round is that? Apparently, all Pak 38 AP ammo was capped.

Shatter can still happen when 'undermatching' happens. The much larger diameter of the 105mm, combined with its low velocity, would greatly reduce the chance of this happening, when compared to the PaK 38.

Early Pak 38 AP was not capped. Shatter has little to do with shell diameter or size and a lot to do with impact velocity. It also has little to do with undermatching. If you have a big enough overmatch then you get penetration anyway in spite of shatter.

I don't get that, but I assume you mean if you have shells to throw away? I would expect that HE shells are cheaper than the specialised alloys, construction and propellants of APs? Also, captured stocks can be used.

At long range the dispersion is greater and more shells are going to be needed to get hits. The longer the range the more shells needed per hit. so how many shells per hit or tank knocked out is acceptable? also consider that for towed AT or open topped vehicles the longer the engagement goes on the greater the likelihood of the enemy artillery joining in. Depends on your HE shells, high explosives may be in shorter supply than steel, fuses aren't cheap and good HE shells require high quality steel. Mediocre ones don't.

Thanks for the Ship armour info. That is Composite Armour though to me (like Chobham). Which is unfair to compare to (most) WW2 tank armour. I expect the iron backing plates were brittle though? – but the join I would expect to negate this?

The steel was the hard brittle part, think of snapping old sword blades, the iron was rolled or wrought iron, not cast iron. Talk to a plumber who has beat on a malleable iron fitting try to crack it by mistake

Thanks for the Sliding Collars info. Also, thanks fro reminding me about the PAW. I think though, that the Puppchen did even better?

I am not sure but at the time it was considered that spinning the projectile (rifling) cut the ability of a given shaped charge design in half.

That's a good one, thanks. This would mean though that a HEAT shell for the FH 18 would easily be able to deal with the T-34 KV? – also, HEAT could have a higher MV than either AP or HE – and thus a longer range, and direct-fire AT ability?

A source gives the HEAT penetration of the 15cm howitzer shell as 160mm so it should have the ability. But in WW II there was a fusing problem and HEAT shells wouldn't function properly at high impact velocities. In some cases the heat shells were fired at less than full charge even by howitzers. So you have the ability to penetrate IF you hit but a lower chance to hit at ranges over 500meters and the chances get worse the longer the range.

The British pack howitzer would've been enough for bunkers? A Boyes AT Rifle would be enough for Japanese tanks otherwise.

The projectile was requested by the Indian Army and pretty much used only by them. Depending on the Boyes would have put the Commonwealth forces at a major disadvantage. Not only were some later Japanese tanks more heavily armored (Type 97) but single penetrations of vehicles by even 12.7-14.5mm bullets doesn't lead to destruction in most cases.

Doesn't it also degrade HE performance though?

Why should it? unless you are trying to shove HE shells through thick armor.

You would need to look at the 2pdr's design brief (, later, the 6, 17, 32pdr's) – though IIIRC it was 30mm @ 1,000 yds. I wonder if this was carried on to the 20pdr after? I expect so (never really went away!).

I am not denying that this ping-pong effect happened at times but It is my opinion that there are too many variables (range, different targets, different impact angles on the same target) to try to design it into a gun/ammo combination. If somebody can show me a design breif that say sthis was a requirement then OK but until then....

1,000 yds is the average combat range. Below that you have allsorts of problems, such as shatter. The best bet is to not let it get that close. If it gets to below 1,000yds, you're probably dead anyway. The C/BC may slow down the round enough @ close range – also, the caps will have deformed – reducing secondary penetration levels. If it does make it out the other side, or into the rear compartment - then I think it will have destroyed the vehicle! (?)

the 1,000yds thing is very Dependant on the year and theater. Early battles in the Dessert often meant holding fire to 600yds or so and the 25pdrs when used as AT guns often held their fire to 400yds or less.

You seem obsessed with this shatter thing. Yes it did happen, more to certain gun/projectile vs enemy tank combinations than others. Some guns never suffered from it. The British 2pdr had a problem with it but that was also because of the face hardened plates the Germans were using on the MK IIIs and MK IVs. Earlier introduction of a capped projectile would have gone a long way in solving that problem. As far as the caps deforming on penetration, they would have been stripped away having done their job. However the cap action was discovered back before 1900 when a target plate was installed backwards on a test range and a projectile went through more armor than it was figured to by entering the soft side first. So if your recapped projectile is trying to exit face hardened armor it may not need it's own cap.

This was the 1st, last method used/intended. The 1st being the WW1 7.92mm 'K bullet', the last being Tungsten Rods HESH. Of course, the 1st 2 would also factor in incandescence… German, Soviet APCR would also factor I here – as would the supposed fragments from the AP/HE. Like I wrote above too, all WW2 ( post-war) British AP Shot was intended for this purpose (along with a possible secondary incendiary effect).

Again, do you have any proof of this?

Post war British APDS ( they didn't really design much post war shot) depended on blowing a hole through the armor. Given the thickness of the targets (no more 15-30mm tin cans) there would be enough secondary projectiles blown out of the armor to cover the question of leathiality

I suppose using Flaks for AT work would wear out the barrels for AA work. IMO though, using them for AA work would wastefully wear the barrels for AT work. Do you think frontline 88mm AA guns were a waste of time? (excepting for AT work).

Front line 88mm AA guns are targets for normal artillery. Once they fire at aircraft their positions are reveled and it would take hours to shift them. This gives the opposing artillery plenty of time to shell them.

 

[Shortround6]

(Part 3).
Arty HE fire doesn't depend on sights so much though? – rather plotting corrections from an observer?

- a lower rate of fire?

I thought the 152mm had more penetration?

loading 40-50kg projectiles vs 25kg projectiles? book figures for towed howitzers list same rate of fire 3-4 per minute but that is with a large gun crew.

See:

http://en.wikipedia.org/wiki/152_mm_howitzer-gun_M1937_(ML-20)

http://en.wikipedia.org/wiki/122_mm_gun_M1931/37_(A-19)

Please note the 152mm HEAT shell was post war.

Hey, that wasn't a joke!

Yes it was, but this needs a thread of it's own.

I think synchro reduces transmission strength though

It depends on original design. If you are trying to fit synchros into an existing gear case you have to make the gears thinner and less strong. If you are designing from scratch and transmission case size is unrestricted there shouldn't be much problem.

Ah, but early PzIIIs had 10 gears – 4 more than the Panthers… ( the KT had 1 more, but was also slower). It's main point was probably the large roadwheels (givin a larger rolling radius) – combined with longer-legged gearing (larger roadwheels up the gearing also).

With low rpm engines you have less over lap of gears. I drive a 34 ton fire truck with a 450hp engine and a 4 speed automatic. While much faster than a tank I think the same principles appliy. Max engine speed is 2200rpm. While it will do 55mph on the level it often is down to 30mph on hill, max rpm in second gear, 1st is good for 15mph. if it shifts to 3rd gear on the hill it is below it's torque and power peaks and can't rev up. More gears mean more options and better mobility in less than flat smooth conditions.

Other things that can affect tank speed are the rolling resistance of the track itself, some designs had twice the rolling resistance of others and track tension. slack track having less rolling resistance. But each of these choices have there down sides too

 

[hartmann]

Hi to all ¡

two parts post

Necking-up is connected to frontal part of a cartridge, not the aft part. Brits have necked-up 57mm to 75mm, but size of breech remained the same; Russkies have necked-up 12,7mm to 20mm, and 14,5mm to 23mm (don't confuse that one with VYa-23 ammo). They all have doubled/tripled shell (projectile) weights, at cost of 1/4 of muzzle velocity.
Sorry, when you said necked-up, I thought you meant necked-down (bottle-necked, Maroschek). I've never heard of what you are talking of before - love new info! So, an oversized projectile was put on a standard cartridge? I've heard about this being done with HEAT warheads on PaK 36s 38s, but never anything else -thanks!

The MG 151 was necked up to 20 mm from the original 15 mm. It was relatively common practice. Both captured Soviet Flak guns, the 76, 2 mm and the 85 mm were necked up to accommodate the standard HE and APCBC-HE shells from the Flak 36 88 mm gun when all the original Soviet ammo was depleted.

I would consider it to be 'prototype PzGr44'?

Probably it was a sort of prototypic PzGr 44. I don't know for sure (as I said previously, there is very little available data).

Is that what happens in deflected shots/shells?

Oh, no ¡ My English… Sorry .
I will explain it:

- Tumbling = the shell/shot is travelling in the air, and starts to yaw.
- Ricocheting = the shell/shot is deflected downwards/upwards when impacts in a plate target.

When you say SVAP - do you mean Super Velocity Armour-Piercing - APDS?

Yes, although I also include APCR and APNCR.

I think some APFSDS spin?

Yes, but It is not worth enough when We like the best results for pure penetration and shot integrity.

The rifling of the gun imparts spin to the APFSDS shot, which also translates in inertial gyroscopic momentum. This means that some energy is lost in heat formation during the contact of the rifling with the sabot by friction, and also, it supposes a high stress to the shot itself.
The rifling in a gun limits the length-to-calibre ratio of an APFSDS shot to some 7 or 10-to-1, when the state of the art APFSDS-T shots fired from smooth-bored guns have a ratio as high as 17 or 20-to-1.

It all depends on the manufacture quality and material used (the APDS manufactured by UK in the WWII were very brittle because inadequate sinterised technology, in contrast to Germany).
What?! The tungsten??

Really, what they use is tungsten carbide alloys (less denser than pure tungsten, and also more brittle if they haven't a good malleable matrix composed of other heavy metals). Putting it simply, the tungsten carbide is made as powder, which binds with other compounds as a "glue".
Quite tricky job

All have pyrophoric effects when they are finely powdered and oxidized.
Would this automatically happen upon penetration?

Yes, It happens automatically when the shot impacts against the plate. The nose is "destroyed" or break and the powder generated, when contacts with ambient moisture, oxidizes and make the pyrophoric effect or flame shown.

You can check in Jentz books some data and drawings concerning this proposal.
Actually, you've jogged my memory. It was intended for the E-75? Which Jentz book please?

The book is "Volume 2 - VK45.02 to Tiger II: ISBN: 0764302248". But he Schiffer editing, not the Osprey (shortened edition)

BTW, the E-75 also had to carry this 105 mm gun.

I heard tungsten was much denser than steel? –

You are correct. The pure tungsten has a density of 19,25 g/cm3 versus the steel which has a density of 7,850 g/cm3 (by comparison the water has only a density of 1 g/cm3).
But…. You have to take in account that the APCR (PzGr 40), and APDS were made from Tungsten carbide, which is something like 14,95 g/cm3. Pure uranium is far denser than steel or tungsten carbide, reaching 19,07 g/cm3 of density.

wonder how the barrel was on the flak version? - how many pieces?...

As far as I know, all the Flak 41 guns had a two pieces barrel.

I wonder if performance would be improved with the standard propellant charge?

Yes, It probably would obtain some 10 to 20 m/s more (maybe even more), but not enough to justify such increase in barrel length without more propellant.

Also, on that point, I wonder what length the barrel should be to burn the propellant entirely

That is very difficult to answer.
It depends on the quality of propellant, quality of obturation, time of burning, maximum admissible chamber pressure among much other parameters (that is inner ballistics, which I am only starting to grasp in).
Actually It is been studied how to burn all the propellant by plasma ignition and so on, but It was not available in 1940s-1950s (even now It is completely experimental).
The fastest answer is: the longer the barrel, the more efficient is the use of the propellant (but also It carries penalties).

I have some scarce data for the 128 mm L66 gun at some 1080 m/s with the PzGr43 versus plates of 80-90 Kg/mm2 strength was punching trough something like 270-276 mm at 30º. With the standard 128 mm L55 gun, it consistently punched through 248 mm at 30º with 950 m/s.
Also I have some data with plates placed at 45º.
Great info - that should do it! (Assuming the IS-3 never had 280mm). Are those angles from vertical? –

They are from the vertical.

So there's 3 different BC designs?: PzGr 39, PzGr 39/43 PzGr 39/43 (2nd design) - ?

The design for the piercing cap and ogive was pretty standard from 1937 to 1943 (the designations of PzGr, or PzGr39), (being very blunt compared to almost all nations) but in 1943 the crh of the ogive was changed, among the form of the piercing cap (hence the new designation PzGr 43), making both them even more blunt to cope with extreme oblique plates.
Those changes, among the differences between big and little cavity of shell, were given different designations.

I was kinda hoping it was a scan from a book. I was wanting to show it to an associate (I wont unless you give me permission).

I think that it was from a manual or BIOS/CIOS document written after the war. You can show the design as It has been already shown in another forum by other people (the photograph is what is not shown by the moment).


Hope this helps

 

[hartmann]

Second part of post

If that photo is a good one, it may show a Ballistic Cap? (Or not). If it's the PPS in that drawing though, then it probably wont (?)

I have been seeing the photo and (excluding the rust which it has in some zones ), it hasn't cap.

It was trialled at captured French Russian carriages, so perhaps they were intending to use it as a towed piece?

Initially, it was intended to be a field gun, but the ballistic qualities were so good that It was changed to AT gun.
The preliminary trials showed that it was too cumbersome, so it was modified to a self propelled AT gun (multipurpose) and adopted in the Jagdtiger and Maus-E-100.

It was trialed at captured French Russian carriages, so perhaps they were intending to use it as a towed piece?
That's the 2nd time my memories been jogged - yes, I remember! What was its intended role there? DP, HE or AT? What was it called? - PaK 44? - if so, that just screams ATG.

Initially It was just called as 12,8 cm K44 (dual purpose) as Tomo said.

IS the 220-228mm if armour the real thickness or effective thickness.

The 220 mm are real thickness, but only at the flanks of the turret.

Thanks for the APCBC info. Before WW1?? Why?? 'Ironclads'?

The firsts APCBC shells were introduced more or less in 1894.

wonder if the PPS round had sliding collars btw?

I think that it had nothing like sliding collars (probably they smoothed the barrel partially, I'm guessing).
The rings were the petals of the sabot, which broke and separated when the shot reached the muzzle (you can guess where the Soviet design of ring petals did origin almost certainly).
Taking in account that in late 1944 and early 1945 the design of the German petals was more similar to the current guns, I would guess that this PPS was from early 1944.

Were the KwK 37 and Italian 47 75mm guns rifled

Yes, they were all rifled guns.

I am afraid the "ping-pong" theory doesn't hold up very well.
1. The Germans certainly didn't intend their AP ammo to ping-pong around the interior. they intended for it to penetrate and then blow up, causing many fragments to fly about in addition to the blast effect.
British AP was intended for this, and seemed to do OK.

The British decision to go for the AP shots without explosive cavity, was more related to the inability to make a fuse which functioned properly more than to be intended for this. The British navy specified APCBC-HE shells with a very big HE cavity.

2. when penetrating thicker armor the metal that came out of the hole forms secondary projectile/s which fly about the interior at high speed.
Very good point - applicable to 'partial penetrations'?.

Yes, the can form plugs or discs which are ejected at the interior, at a very similar velocity to the shell when impacts.

The last numbers in the year usually signify the year of adoption or design, but not always.

Quite correct Shortround.

Originally Posted by schwarzpanzer
At closer ranges, the 105mm will not suffer shatter, but the 50mm will/might(?). BTW did the LFH fire AP, APC, APCBC or APCR rounds? and did they have HE content? - always puzzled me, that one, perhaps now I'll finally find out! The shell I saw though, looked like blunt-nosed APC - so would seem to me to be less likely to bounce off the T-34s armour than the pointed 50mms? No idea if it had HE content or not, but IIRC it didn't - which would make shatter even less likely.
It might have been APHE,

Yes, Initially It carried a plain AP-HE shell.
Sometime after, they used APCBC-HE shells, although not in the way that is conventional, and in very limited use.
The main way to defeat tanks with the 105 mm howitzer was with HEAT ("Hohlladung") rounds.

AP (BR-271SP).

This was an APBC solid shot (SP means "Sploschnoyi" or "Solid").

This is why I'm surprised APHE wasn't dropped on the bigger guns - APCBC had much better performance.

The main reason was that manufacture high performance APCBC-HE shells was far more complex and technology demanding than simple monoblock AP-HE shells.

Then again, apparently the D-10 used Naval ammunition, so that may explain why?

Concerning HE ammo, It was true, because the D-10 gun was directly derived from an antiaircraft gun, but when they used It as AT gun, they lacked this kind of AP ammo and had to design it from zero point (and had to use the same design that was used in previous guns).

True. The 122 was available - as the A-19 and in the SU-122.

The D-25 gun was derived from the A-19 field gun, but the 122mm gun carried in the SU-122 was a howitzer, the M-30. The M-30 never carried AP-HE shells as far ass I know, only HE and HE-frag (although they obtained some HEAT shells late in the war).

all Pak 38 AP ammo was capped.

The first PaK 38 PzGr shell was uncapped. The PzGr 39 was an APC-He shell, and the last series, the PzGr 39/42 was an APCBC-HE shell, almost only issued to the 5 cm Flak 41.

Hope this helps