Alternative light and anti-tank guns, 1935-45

[Shortround6]

- 88mmL56 gun on the 10.5cm howitzer carriage - far less clumsy than the Pak 43, but main advantage is that it can be done fairly early, like before ww2. If Goering is against this, see what can be agreed with the Navy. It should also make the alt-Nashorn being a lower target, FWIW.
- 7.5cmL70 gun on the 10.5cm how carriage - sorta German 17 pdr for all intents and purposes.

Nope and nope.

The 88mmL56 gun in the Tiger went 1332kg including muzzle brake. The poor 10.5cm howitzer carriage is not going to stand up to that.

The 7.5cmL70 gun was about 1086kg.
The 17pdr gun was about 827kg (being around 1.5 meters shorter helped)

Not saying you can't develop a towed mount for either gun, but the standard 10.5cm howitzer carriage is not going to be a short cut.

Edit. Let's remember that the very early 17pdr on the 25pdr carriage could only aim about degrees each side without using the turntable.
Trying to point one of these high power guns 20-30 degrees off axis was not going to end well.

 

[z42]

Good points. A few comments:

The whole idea of using capped shot is that uncapped shot tends to shatter/break up with impacts approaching 2500fps/ 750mps but this depends on the armor and the heat treatment of the projectile.
You can use capped shot at impact velocities of around 3000fps/900mps but after that you tend to need Tungsten.

Yes. You can fit a cap to an APCR projectile as well?

Please note that 57mm AT guns had a velocity of round 4000fps and needed tungsten to work. Also note that APDS core made of tungsten weighed a lot more per unit of frontal area than a steel projectile and would retain velocity better.

During the cold war the Soviets made APFSDS projectiles using steel as an alternative to tungsten or depleted uranium. Not sure if these were used by the Soviets themselves or was it only for export customers? And to be fair, these used a variety of steel that was invented after WWII, so called "maraging steel". But still, very high velocity compared to anything during WWII.

As for the density of steel vs tungsten, yes I'm aware. Either you need to make the penetrator thicker to compensate, or then you'll have to live with poorer ballistics.

 

[ThomasP]

re

You can fit a cap to an APCR projectile as well?

Yes. In fact, most (I think) post-war APCR and APDS were fitted with piecing caps of one form or another. Some of the modern APFSDS also have piercing caps as well.

re

During the cold war the Soviets made APFSDS projectiles using steel as an alternative to tungsten or depleted uranium

The early 115mm APFSDS used the ~equivalent of T2 tool steel, a form of cutting steel widely used in machining.

 

[tomo pauk]

Nope and nope.
The 88mmL56 gun in the Tiger went 1332kg including muzzle brake. The poor 10.5cm howitzer carriage is not going to stand up to that.
The 7.5cmL70 gun was about 1086kg.
The 17pdr gun was about 827kg (being around 1.5 meters shorter helped)
Not saying you can't develop a towed mount for either gun, but the standard 10.5cm howitzer carriage is not going to be a short cut.

That would be 'yes and yes'.
The Pak 43 started out using the carriage of the 10.5cm howitzer + the wheels of the 15cm howitzer. The ordnance as installed on the Tiger II weighted 2265 kg, with just the barrel weighting 1155 kg. A far easier set-up would've been if the gun in question is the smaller and lighter 'Tiger's gun', let alone the 'Panther's gun'.

Edit. Let's remember that the very early 17pdr on the 25pdr carriage could only aim about degrees each side without using the turntable.
Trying to point one of these high power guns 20-30 degrees off axis was not going to end well.

I will not try and suggest that Germans revert to using a 1-legged carriage that many years after the ww1.

 

[tomo pauk]

IIUIC these were never made in numbers, so there was never a big batch of them available for conversion into AT guns.

They might've been much more than the footnote that the Dickermax and Sturer Emil were. As well as being in the frontline already in 1939.

Germans can also impress the captured heavier (70+ mm) AA guns into the AT role. Be it as-is (lighter guns preferably), or outright converted into the AT guns.

I think the undoing of all these is the weight. A Stug III cost about 6 times as much as a PAK 40, not including the prime mover. Yes, fewer barrels for the same price, but might be a better investment as the better mobility and protection makes it more likely to survive for the next day?

As a slight aside, the 75L70 was pretty good. Smaller and cheaper than the 88L56, yet better penetration. Good enough for practically anything armored it was going up against for the entire war.

Yes, once past some weight limit the AT guns become as much as an asset as they are a liability. IMO, the price comparison should include a cost of the prime mover, and the heavy AT guns will require a potent prime mover - these don't come in cheap, and will still be problematic to be used on a terrain that can combine slopes with snow or mud.

One of the reasons the 75L70 was cheaper was because it's barrel life was lower by factor of 3(!). At the distances we might require the busting of enemy tanks by these heavy guns (beyond 1000m), the penetration advantage of the 75L70 went down under single digits in %, and the 88mm was more accurate if both guns were using the APCR ammo.
(bigger HE shell that 88mm had was probably of tertiary importance for an AT gun)

Probably the main advantage of the 75L70 was that it was very compact (or it was that the Tiger's gun was too voluminous?, enabling it to be installed into a smaller turret.

 

[Shortround6]

equivalent of T2 tool steel

T2 tool steel contains 17.5-19% tungsten which may give it several advantages over some other types of tool steel. It may also have given some advantages over the tungsten alloy used in some western penetrators. Trying to make long skinny penetrators out of some tungsten carbide materials may not have worked well because tungsten carbide is rather brittle and may not like bending forces. It also may be more difficult to manufacture the desired shapes even through the long skinny penetrator part appears simple. Scrap rate may have been a concern.

 

[Shortround6]

he Pak 43 started out using the carriage of the 10.5cm howitzer + the wheels of the 15cm howitzer.

Some sources say that they used the trail arms + the wheels of the 15cm howitzer.
Which seems to make more sense.
Width in travel mode.
10.5 cm leFH 18..................1.977 meters
15 cm sFH 18.......................2.255 meters
Pak 43/41..............................2.527 meters.
Sticking wider wheels on the 10.5 chassis doesn't seem to quite cover it. Neither does adding up the weights.

I will not try and suggest that Germans revert to using a 1-legged carriage that many years after the ww1.

Not saying you were.
I am trying to say that the British accepted a substantial limitation on the first 100-150 17pdrs to get them into the 25pdr carriages.
I am trying to head off the "British did it so the Germans could have" argument.
I will also note that the US 3in AT gun M1 went about 2211kg but may never have seen combat in the 105 howitzer shield.

Service guns got a larger, heavier shield
The proper 17pdr MK I guns with 60 degree carriages went 2923kg in firing position and 3040kg traveling. They were 2.225 meters wide traveling. The gun was shorter and lighter than the German 7.5cmL70 barrel.

Probably the main advantage of the 75L70 was that it was very compact (or it was that the Tiger's gun was too voluminous?, enabling it to be installed into a smaller turret.

This may have been part illusion?

The Panther gun was only 219mm longer than the 88mm, Yes the 88mm barrel was fatter near the back. How big the recoil systems inside the turret were?
and ammo?

 

[tomo pauk]

Some sources say that they used the trail arms + the wheels of the 15cm howitzer.
Which seems to make more sense.
Width in travel mode.
10.5 cm leFH 18..................1.977 meters
15 cm sFH 18.......................2.255 meters
Pak 43/41..............................2.527 meters.
Sticking wider wheels on the 10.5 chassis doesn't seem to quite cover it. Neither does adding up the weights.

I'll check out the article in the Waffen Revue no.37 and, hopefully, come out with a more definitive answer to this ... mystery.

Not saying you were.
I am trying to say that the British accepted a substantial limitation on the first 100-150 17pdrs to get them into the 25pdr carriages.
I am trying to head off the "British did it so the Germans could have" argument.
I will also note that the US 3in AT gun M1 went about 2211kg but may never have seen combat in the 105 howitzer shield.
Service guns got a larger, heavier shield
The proper 17pdr MK I guns with 60 degree carriages went 2923kg in firing position and 3040kg traveling. They were 2.225 meters wide traveling. The gun was shorter and lighter than the German 7.5cmL70 barrel.

My erstwhile idea was: "okay, Germans shoehorned the heavy brute (= the ordnance of the Pak 43), on the carriage of the 105mm how and gotten themselves a good if not great weapon, so they will have easier time to install the lighter and less powerful gun on the same carriage".
Major bonus being the much earlier availability if they go with the 88mmL56, talk already pre-war.

This may have been part illusion?
The Panther gun was only 219mm longer than the 88mm, Yes the 88mm barrel was fatter near the back. How big the recoil systems inside the turret were?
and ammo?

I'm afraid that the smaller size of the Panther's gun was not an illusion. I've converted the photo into a pdf format and measured the turret widths in a pdf viewer; never mind the 'm's. Turrets start in the ballaprk wrt. the width, but the Panther's turret slopes sharply towards the roof, making it much smaller on average. Also note how much the commander's cupola 'dominates' the roof of the turret, not the case with Tiger.

 

[tomo pauk]

Per the W. Revue no.37, the carriage used for the Pak 43/41 was that of the '10,5cm leichte Kanone 41 L40", that original weapon remained stillborn. So the carriage was definitely stronger than what was used on the 10,5cm lefh 18.

 

[z42]

My erstwhile idea was: "okay, Germans shoehorned the heavy brute (= the ordnance of the Pak 43), on the carriage of the 105mm how and gotten themselves a good if not great weapon, so they will have easier time to install the lighter and less powerful gun on the same carriage".
Major bonus being the much earlier availability if they go with the 88mmL56, talk already pre-war.

Yes, they could have made a 88L56 PAK already before the war, but why? Tanks with thick enough armor to require the performance of that gun weren't really a common thing until quite late in the war?

In retrospect, if I were in charge of German (anti-)tank guns, my early-mid war priorities would be to replace the 37mm PAK and the 37mm armed Pz III with the 50mm gun (preferably before rolling into France), and roll out the 75L43/L48/PAK40 ASAP, both to replace the 75L24 on the Pz IV, and to have the next gen (anti-)tank gun rolled out by the time the 50mm is no longer sufficient.

 

[tomo pauk]

Yes, they could have made a 88L56 PAK already before the war, but why? Tanks with thick enough armor to require the performance of that gun weren't really a common thing until quite late in the war?

Direct fire on the strongpoints was a thing centuries before the tanks, so a potent gun for direct fire to be used against the Czech, Belgian or French fortifications, blockhouses and the like would've not been anomaly. Germans were using the 88mm Flak in direct-fire role in Poland and IIRC during the Spanish CW. A simple expedient of adding the 'proper' AT ammo is not a big deal.
We can also recall that French were fielding the well-armored tanks several years before ww2. Certainly, Germans will not be aware of the armor protection up to the last milimetre before capturing one, but being safe rather than sorry was a thing, and still is; ditto for the tanks receiving armor upgrades.

The 88mm cannon on the 105mm howitzer might've also do well as a long-range piece, even if the elevation would've been restricted.

In retrospect, if I were in charge of German (anti-)tank guns, my early-mid war priorities would be to replace the 37mm PAK and the 37mm armed Pz III with the 50mm gun (preferably before rolling into France), and roll out the 75L43/L48/PAK40 ASAP, both to replace the 75L24 on the Pz IV, and to have the next gen (anti-)tank gun rolled out by the time the 50mm is no longer sufficient.

Me - I wouldn't be bothering with the 37mm on anything heavier than 10 tons, bar as a counter-intelligence stunt and for export. Start with 5-5.2cm weapon, move onto the 7.5cm weapon that is a more powerful than the Fench/US/Polish 75mm M1897, or in the ballpark of the Soviet 76mm divisional guns - all before 1941. MV of 800+ m/s for the smaller weapon, and 650+ for the 7.5cm*. Both as AT and tank guns.
The weapons based on the 7.5cm Flak and on the 8.8cm L56 on the backburner, ie. a few dozen to be tested out in 1940; ~850 m/s as a goal.

*all for the 'full weight' projectiles

Stop making the 3.7cm pak/kwk as soon as possible for the needs of Heer.

 

[Elan Vital]

The Panther gun was only 219mm longer than the 88mm, Yes the 88mm barrel was fatter near the back. How big the recoil systems inside the turret were?
and ammo?
View attachment 801979

I'm afraid that the smaller size of the Panther's gun was not an illusion. I've converted the photo into a pdf format and measured the turret widths in a pdf viewer; never mind the 'm's. Turrets start in the ballaprk wrt. the width, but the Panther's turret slopes sharply towards the roof, making it much smaller on average. Also note how much the commander's cupola 'dominates' the roof of the turret, not the case with Tiger.

View attachment 802059

The 88mm KwK 36 had relatively similar power to the Soviet 85mm tank guns, but the latter put a lot of effort in the development of a compact mount so the installation was a good deal narrower. The KwK 43 in the Tiger II was reworked with a much more compact mount as well which is a good part of why the narrow turret front was possible in spite of the increased power of the gun. The Panther improved on the Tiger I to some degree, but introduced other problems (very front heavy turret), and it's only with the Schmalturm and reworked mount that the 75mm L70 became truly compact.

There was a similar situation with the 75mm M3 and 76mm M1 in the Sherman as opposed to the British 75 and the Soviet 76mm guns.

The Soviets on the other hand consistently had to deal with inferior propellant which resulted in somewhat bigger charges than Western equivalents (or limitations owing to the pressure curve of said propellant). I've seen arguments that German WW2 guns/propellant had not been pushed to the same level as that of other Western countries, but cannot confirm.

 

[bf109xxl]

The 88mm cannon on the 105mm howitzer might've also do well as a long-range piece, even if the elevation would've been restricted.

With the increased speed of tank movement on the terrain and the greatly increased number of tanks, the concentration of anti-tank artillery became a decisive factor, which required a quick change of position. For all its effectiveness 88 it was a bulky and very expensive gun, the use of which against tanks was a forced measure. During the war, even the 75/76 mm caliber was excessive with a rational projectile design. The smaller effective kill radius was compensated by less visibility on the battlefield. Having a lot of expensive, heavy and low-mobility guns was a sure way to defeat.

 

[tomo pauk]

For all its effectiveness 88 it was a bulky and very expensive gun, the use of which against tanks was a forced measure.

There was no in-service 88mm AT German gun like the one I've suggested.

During the war, even the 75/76 mm caliber was excessive with a rational projectile design.

No amount of rationality will make the the 75-76mm guns - bar the 17 pdr and the 75mmL70 - effective against all comers back in ww2 unless there is enough of tungsten available.

Having a lot of expensive, heavy and low-mobility guns was a sure way to defeat.

Rest assured, there will never be a lot of expensive AT guns around.

 

[bf109xxl]

There was no in-service 88mm AT German gun like the one I've suggested.

The Pak 40 was already too heavy and insufficiently maneuverable. Why use 88mm if the Pak 40 was doing so well? Well, yes, with the IS-2 and the M26 would have been a problem, but even for their sake it was not necessary to improve anything. Anti-tank artillery would have higher casualties, but in the end it would have been more profitable than reducing gun production and rolling out new ammunition. The only thing that changed the situation was the appearance of the T-44, a medium tank with heavy armor, but they did not participate in the war.

No amount of rationality will make the the 75-76mm guns - bar the 17 pdr and the 75mmL70 - effective against all comers back in ww2 unless there is enough of tungsten available.

Even with a steel core, the PzGr.40 provided adequate armor penetration at actual combat ranges.

Rest assured, there will never be a lot of expensive AT guns around.

In the post-war world, there were plenty of expensive anti-tank guns, which was driven by an even greater number of even more expensive tanks with powerful armor. But the Germans needed to provide quantity, the quality was already high enough. Any solution that reduced production volumes was unacceptable to them. It is good that they realized it too late.

 

[tomo pauk]

<snip>

Considering the effort Germans put into the hole-punching guns far more powerful than the Pak 40, seems like they were of a much different opinion than what you are thinking wrt. the abilities of the Pak 40.
These guns were also to shoot the tungsten-cored ammo, again pointing out that their opinion on the steel-cored ammo was very different to yours.

 

[Elan Vital]

So did the Soviets. Meanwhile, the British still put the 17pdr in service which was not even all that weight-efficient but was nearly as powerful as the L70 (certainly more than the PaK 40).

The British worked on a towed 32 pounder and the US experimented with towed versions of respectively the 76 M1, the 90 M3, IIRC the 90mm T15 and the 105mm L65; and postwar the same 76mm as the M41 Walker Bulldog. While some were certainly rejected due to excessive weight, it is likely that the end of the war and the quick progression of shaped charge weapons contributed to these heavier guns not entering service.

 

[bf109xxl]

Considering the effort Germans put into the hole-punching guns far more powerful than the Pak 40, seems like they were of a much different opinion than what you are thinking wrt. the abilities of the Pak 40.
These guns were also to shoot the tungsten-cored ammo, again pointing out that their opinion on the steel-cored ammo was very different to yours.

No one could forbid them from suffering perfectionism, which only accelerated their defeat.

In addition. Penetration for the Pzgr.40(W) without tungsten core (angle of impact 60°):

Distance [m]	Thickness [mm]
100	80
500	75
1000	63

It was absolutely enough to fight all tanks except the IS and M26, the latter were not so many and there would be enough tungsten for them.

 

[tomo pauk]

No one could forbid them from suffering perfectionism, which only accelerated their defeat.

As one can read in this forum, I'm mostly trying to suggest off-the-shelf stuff, not the perfect stuff.

 

[bf109xxl]

As one can read in this forum, I'm mostly trying to suggest off-the-shelf stuff, not the perfect stuff.

My words referred exclusively to the military leadership of the Reich and no one else.