Tank & AFV armament alternatives, 1935-45 (2 Viewers)

[tomo pauk]

The Churchill Mk I of Dieppe fame had a hull mounted Ordnance QF 3-inch howitzer (76 mm) in 1942.

Yes, indeed.
Still not beating the French, though - the 3in howitzer was a very weak cannon.

 

[Shortround6]

Comparing the British guns listed earlier and the French guns from the link Tomo has provided.

holes needing to be punched.

gun.......................size hole/sq cm
13.2mm....................1.368
20mm.......................3.142
25mm.......................4.909
37mm....................10.752
40mm....................12.566
47mm....................17.35
50mm....................19.635
57mm....................25.52
75mm....................44.18

British guns
2pdr AT gun....... = 337,782 joules (original load)
2pdr AT gun .......= 391,800 joules (HV load)
3pdr tank gun....= 231,000 joules
6pdr short gun..= 230,000 joules (WW I late)
6pdr long gun.. = 397,000 joules (WW I early)
6pdr AT gunL43 =927,380 joules (early shot)
3in howtizer HE = 102,680 joules (+ edit)

American
37mm AT/Tank.= 320,324 joules.
75mm Pack H...= 483,900 joules.
French guns.
13.2mm................= .16,640 joules
25mm...................=123,900 joules
37mm short.......= .70,200 joules (APCR)
37mm long........=171,000 joules
47mm short.......=149,850 joules
47mm long........=367,500 joules
47mm AT gun...=677,490 joules
75mm 1897.......=1,039,680 joules (estimate)
75mm short.......=706,880 joules (+ edit)

German
75mm Pak 40 = 2,132,698 Joules

Soviet
76.2mm/L 16.5 inf.....= 464,284 Joules.

Velocity matters.

I will try to add more later.

 

[Shortround6]

Yes, indeed.
Still not beating the French, though - the 3in howitzer was a very weak cannon.

More like a real life nerf gun with smoke shells.

 

[tomo pauk]

French guns.
...
75mm 1897.......=1,039,680 joules (estimate)

That seems to be true for the Polish ammo for that gun, at least when looking here (note: the HL/HEAT shells listed in the tables there were of German production, fitted on the French casing, and, probably, using French propellant)
French seem to have been loading their 75 M1897 ammo lighter?

 

[Shortround6]

That seems to be true for the Polish ammo for that gun, at least when looking here (note: the HL/HEAT shells listed in the tables there were of German production, fitted on the French casing, and, probably, using French propellant)
French seem to have been loading their 75 M1897 ammo lighter?

That is what I used but I guessed at the weight of the projectile at 6.4kg.
Since there is a lot (dozens) of loads for the 75mm 1897 (and US tank guns) things are going to vary more than a bit.

A 75mm is trying to make a hole over 4 times the size of the 37mm so we need over 4 times the joules assuming an equal projectile construction/technology.

US was claiming 2900fps for it's 37mm AT/tank gun which is 320,324 joules.

The 75mm field guns are not going to punch more armor than a good 37-40mm gun assuming similar projectile design.

 

[tomo pauk]

The 75mm field guns are not going to punch more armor than a good 37-40mm gun assuming similar projectile design.

The 75mm field guns will be punching through more armor than the good 40mm and under. See the M1897, it should be able to penetrate 58mm at 1000m at 30 deg, vs. the 2pdr incapable to do the same at 500 yds with the best full-weight ammo. American 75 mm was supposed to be as good as the F/P 75mm with the L31 barrel.
The more modern guns than the M1897, like the different Soviet guns, as well as the n.A.16 and FK 38, will be doing even better. Even the weakest of them were with 25% greater propellant load than the Polish ammo for the M1897. The Italian 75/34 will also be doing better then the M1897.

 

[tomo pauk]

To expand on this 40mm vs. 75mm thing.
British have tested the different guns vs. the different German tanks in the Middle East in mid 1942. They found, for example, out that the 2pdr HV shot will not penetrate at all the 30+30mm front armor of the up-armored Pz-III and -IV, while the worst AP ammo for the US (the 'SAP' - probably APHE?) will still do it at distances between 400 and 500 yds. The APC ammo for the US 75mm will still penetrate 30+30mm at under 1000 yds.
The 50mm frontal armor of the Pz-III of 1942 will be penetrated by the 2pdr HV shot at under 400 yds, while the SAP 75mm will do it between 600 and 700 yds, and the APC will do it between 1500 and 1700 yds.
(data per 'Panzertruppen 1933-42' book by T. Jentz)

We can just imagine how much of an asset even the 19 century 75mm gun turned into a tank gun would've been on the battlefields between early 1940 and early 1942.

 

[Shortround6]

To expand on this 40mm vs. 75mm thing.
British have tested the different guns vs. the different German tanks in the Middle East in mid 1942. They found, for example, out that the 2pdr HV shot will not penetrate at all the 30+30mm front armor of the up-armored Pz-III and -IV, while the worst AP ammo for the US (the 'SAP' - probably APHE?) will still do it at distances between 400 and 500 yds. The APC ammo for the US 75mm will still penetrate 30+30mm at under 1000 yds.
The 50mm frontal armor of the Pz-III of 1942 will be penetrated by the 2pdr HV shot at under 400 yds, while the SAP 75mm will do it between 600 and 700 yds, and the APC will do it between 1500 and 1700 yds.

We can just imagine how much of an asset even the 19 century 75mm gun turned into a tank gun would've been on the battlefields between early 1940 and early 1942.

We are dealing with about 3 things here.
Comparing the Joules only works at the muzzle. Large shot retains it's velocity better everything else being equal, which it seldom is, see below.
Germans were using face hardened armor in the extra plates applied over the base plates. This affected the performance of uncapped shot more than capped shot. American M72 shot was not capped.

American M72 plain (uncapped) shot 13.92lbs. compare with the ABC M61 shot

Which is actually APCBC shot. It weighs 14.96 but is fired at the same velocity so it starts with about 7.5% more energy.
The pointy means it arrives at higher speed, (even more striking energy) and the piercing cap helps out with face hardened armor, depending on striking angle.
What the 2pdr got was more gun powder behind a projectile that was very close in style/technology to the M72. Being a light projectile it slowed down quicker, Starting out at about 200m/s faster it slowed down at a quicker rate over the same distance. Getting it's own APCBC projectile would not eliminate the difference but it would reduce the difference. The higher striking velocity of the small shot meant it was affected by face hardened armor more.

If your 1930s army can afford tanks that are several tons heavier (even with thin armor) then maybe the modified 75mm field guns make sense. But if you are trying to keep your tanks cheap (and have them fit on existing bridging/transport equipment) so you can afford more than few handfuls you are buying more than is needed.

 

[tomo pauk]

We are dealing with about 3 things here.
Comparing the Joules only works at the muzzle. Large shot retains it's velocity better everything else being equal, which it seldom is, see below.

You don't need to sell me the larger (heavier) shots

Germans were using face hardened armor in the extra plates applied over the base plates. This affected the performance of uncapped shot more than capped shot. American M72 shot was not capped.

At any rate, the field gun of ww1 vintage is still coming ahead vs. the 2pdr when both are firing the uncapped shot. Even the US 37mm APC shot, that is better per the British tests than the "HV" AP shot (still 2800 ft/s), is coming in behind the SAP 75mm. The US 37mm APC was found as able to penetrate the 30+30mm armor, even if it is at 200 to 300 yards (where the 2pdr HV makes no penetration at all).

What the 2pdr got was more gun powder behind a projectile that was very close in style/technology to the M72. Being a light projectile it slowed down quicker, Starting out at about 200m/s faster it slowed down at a quicker rate over the same distance. Getting it's own APCBC projectile would not eliminate the difference but it would reduce the difference.

British say here that the 2pdr APCBC gains just 3mm over the HV shot at 500 yds, and 6mm at 1000 yds. That is a poor return for when the shot was available (1943), where the capped 75mm shot from the ww1 vintage weapon does at 1000 yds what the capped 2pdr does at 500 yds (and still must call help when the target appears that the 2pdr ammo is badly suited for).
British tankers and mechanics were up-gunning their tanks with 75mm guns for good reasons.

If your 1930s army can afford tanks that are several tons heavier (even with thin armor) then maybe the modified 75mm field guns make sense. But if you are trying to keep your tanks cheap (and have them fit on existing bridging/transport equipment) so you can afford more than few handfuls you are buying more than is needed.

In my opinion, if the tank is already in the paper stage over 15 tons, it needs to have a good-sized gun. 47mm is probably the minimum (45 if you're Soviets), or a short 75mm (like the Kwk 37, or it's Soviet equivalent, or the 75mm pack howitzer), with an eye for up-gunning. Possibly even making the mix of the two versions, talk 2/3rds small gun, 1/3rd bigger gun?
If the tank is in paper stage over 20 tons (a lot of these were actually made before 1940), it needs to have a 75-76mm, with the equivalent of the French short 75mm or the German Gebirgs 36 being the weakest option.
If a tank is planned for 25 tons and above (again a good deal of these were actually made before 1940), a good 75mm - at least as good as the M1897 - is the lowest bar.

The 57 mm gun might be a good alternative here for the under 20 ton tanks.

 

[Shortround6]

For the British and this might sound harsh, Just about every tank they built was pretty much trash until around 1942-43 and it had nothing to do with the guns.

They actually didn't know what they wanted the tanks to do, they had theories but their theories didn't match realities (they were not the only ones).
Building larger tanks with larger guns was not going to save the situation.

Yes the 2pdr was well past in prime in mid 1942. Think about that.
After nearly 3 years of war and several years of trying to build both cruiser and infantry tanks in the late 30s the Americans show up with warmed over 1897 75mm gun in a tank that is about 50% heavier, around 2 ft taller (American version is another foot taller to the top of cupola and has some real tactical problems. Americans had not figured out yet how to put the 75mm gun in a rotating turret. It was both size and not cracking the turret race with the recoil forces. This kind of depends on the size/power of your gun. It is easier to put in a low powered 75mm.
And yet the 2pdr, with it's old ammo, is not too far behind the American/French 75mm, it is about equal to the German short 50mm.
Germans are surviving because they were able to stick 60mm of armor on some of their tanks, in places. Crusader's had thinner armor in many places.
British scraped by using the Infantry tanks with heavy armor but slow speed, an admission that your tank designs aren't working.

Use the 2pdr while they learned to build tanks, ones that worked. Figure out what is wanted, like something in the middle, not the extremes the British favored. Heavy armor but bog slow or fragile (in several ways) but fast. Yes they kept the 2pdr to long. They also, while not shooting the 6pdr in the foot, wacked the foot pretty good with a large hammer. Given the similar projectile to the US M61 a 6pdr could go through a MK III with 60mm of armor at just under 2000yds or just over, depending on barrel length. This does assume the British actually put on a sight/scope that can be used as that distance.

A lot of importance is placed on the Germans ability to use HE ammo from their tanks. It may have been a bit over blown.
At El Alamein the Germans had about 64(?) tanks with 75mm guns (of three types) but about 173 (?) tanks with 50mm guns. And another 250-300 of smaller, older tanks (including Italian). I could be wrong but I don't think the earlier battles had significantly different proportions. So about 25-33% of the main German tank force had 75mm guns but they get most/all of the credit for the German use of HE shells in battle? Not saying the Germans didn't use it and use it well. And when the British don't have ANY HE until mid 1942 there was an advantage. Again the British shot themselves in the foot (other one from the crappy AP ammo). Germans were NOT lobbing around large quantities of 75MM shells. They were firing a lot of 50mm HE. Both sides had trouble with supporting artillery keeping up with moving battles, both with mobility and communications.

Give a 75mm gun to the bozos that built the Covenanter and see what kind of mess you get.
Let's not forget that over in Infantry Tank Land this made it's public debut on Oct 6th 1940.

It did have the 75mm gun (or mock up?) from a Char B 1 in the front plate. Early drawings show a 2pdr out each side in WW I style sponsions.
90 tons(?).

 

[tomo pauk]

Yes the 2pdr was well past in prime in mid 1942. Think about that.

As a tank gun, the 2pdr was past it's prime when it was 1st installed on a tank.

After nearly 3 years of war and several years of trying to build both cruiser and infantry tanks in the late 30s the Americans show up with warmed over 1897 75mm gun in a tank that is about 50% heavier, around 2 ft taller (American version is another foot taller to the top of cupola and has some real tactical problems. Americans had not figured out yet how to put the 75mm gun in a rotating turret. It was both size and not cracking the turret race with the recoil forces. This kind of depends on the size/power of your gun. It is easier to put in a low powered 75mm.

Churchill was heavier than the M3 Medium by some 10 tons, it's hull-mounted gun was barely better than a 3in mortar, and the gun in the turret was without the HE shells; the AP shots were of a design as if someone designed them before ww1. Both guns on the M3 were a tad better in AP abilities than what the Churchill had. Churchill was the bulkier one, and was slower. It was also better armored.

Both Americans and British could've went with a gun of the power similar to what the pack howitzer had for installation in the turrets in the second half of 1930s, and move up from there.

Use the 2pdr while they learned to build tanks, ones that worked. Figure out what is wanted, like something in the middle, not the extremes the British favored. Heavy armor but bog slow or fragile (in several ways) but fast. Yes they kept the 2pdr to long. They also, while not shooting the 6pdr in the foot, wacked the foot pretty good with a large hammer. Given the similar projectile to the US M61 a 6pdr could go through a MK III with 60mm of armor at just under 2000yds or just over, depending on barrel length. This does assume the British actually put on a sight/scope that can be used as that distance.

Install a darned 6pdr gun as soon as 1935, if not earlier. Who cares if it is not as good as the historical 6pdr of ww2 fame.

A lot of importance is placed on the Germans ability to use HE ammo from their tanks. It may have been a bit over blown.
At El Alamein the Germans had about 64(?) tanks with 75mm guns (of three types) but about 173 (?) tanks with 50mm guns. And another 250-300 of smaller, older tanks (including Italian). I could be wrong but I don't think the earlier battles had significantly different proportions. So about 25-33% of the main German tank force had 75mm guns but they get most/all of the credit for the German use of HE shells in battle? Not saying the Germans didn't use it and use it well. And when the British don't have ANY HE until mid 1942 there was an advantage. Again the British shot themselves in the foot (other one from the crappy AP ammo). Germans were NOT lobbing around large quantities of 75MM shells. They were firing a lot of 50mm HE. Both sides had trouble with supporting artillery keeping up with moving battles, both with mobility and communications.

This is one of the good reasons why people were trying to have their tanks shoot HE ammo, even if it was not of ideal size/weight - everyone's artillery in the 1930s was bad in following the tanks in the maneuvers the tanks of the day were capable of. The accompanying infantry will be also grateful to have the HE-capable tanks around them when advancing.

Give a 75mm gun to the bozos that built the Covenanter and see what kind of mess you get.

For my money, British making more and improved infantry tanks instead of the cruiser tanks is more than okay.

 

[yulzari]

Let us remember that the British got the 2Pounder as the tank version of the AT gun and both was cheaper than a separate tank gun and perfectly adequate as a hole puncher at the time. Mean while they developed the 6 Pounder and planned to put it into production replacing the 2 Pounder in late 1940. But then France fell and Britain needed many AT gun now not better ones next year. When the 6 Pounder went into production Vickers were developing the 75mm HV and the 17 Pounder to replace the 6 Pounder but the gunmakers and turret maker were drinking in different pubs so the 75mmHV did not fit into the new turrets. Hence the Challenger and the improvised Firefly.

I went into the turret of a Firefly once and was not sure I could get out. Without the new loaders hatch I doubt if I could have got in never mind get out. Rather like being in a metal lobster pot full of pointy bits and a small recoiling telephone box.

So, had the planning been carried into action, Britain would have had top tier tank guns throughout the war. But no plan survives contact.

A story passed on to me of an old Regular tin can soldier who was in the Battle of France was that they were told to use the 2 Pounder AP against AT guns by hitting the ground in front of the AT gun as the tumbling ricocheting AP round would do more damage than a 40mm grenade. My Yeomanry predecessors in 1944/5 nevertheless did not fit the supplied Littlejohn Adaptor so that they could fire HE rounds from their Daimler Armoured Car 2 Pounders.

 

[tomo pauk]

Let us remember that the British got the 2Pounder as the tank version of the AT gun and both was cheaper than a separate tank gun and perfectly adequate as a hole puncher at the time.

Role of a tank gun was not to be cheap - especially if the intent is to install them on expensive tanks - but to offer adequate firepower against the all comers it can realistically meet. The set of the possible and likely targets for a tank's main gun was already more or less known back from the days of ww1. British planners didn't need us in 21st century to specify that a tank gun should also be a good HE thrower, but they opted to forget that when specifying the 3pdr, 2 pdr and 6 pdr (initially without the HE shell). They also didn't need us to tell them that a 6 pdr is superior in that regard than a 3 pdr, let alone a 2 pdr, but alas.

Trying to issue the CS versions of the tanks also nixes the talk that going with a 2pdr is a cheap option. All the talk about the 2pdr being cheap (= good) forgets that servicemen using the tanks are/were not cheap.

So, had the planning been carried into action, Britain would have had top tier tank guns throughout the war. But no plan survives contact.

Planing was bad. From going too small with the guns, not issuing them HE shells (bar the CS tanks, that were useless as hole punchers, and HE ammo was minority of the ammo loadout) until late in 1942, not making the turret and gun to fit - two times.

 

[Shortround6]

As a tank gun, the 2pdr was past it's prime when it was 1st installed on a tank.

If so, everybody was installing guns that were passed their prime. A 9 prototype had one in 1936, production started in 1937, slowly, but that was not the fault of the 2pdr gun.
Who was installing anything better in 1937 in most of their tanks?
French were building how many 37mm armed tanks for every one with a 47mm or larger.

Churchill was heavier than the M3 Medium by some 10 tons, it's hull-mounted gun was barely better than a 3in mortar, and the gun in the turret was without the HE shells; the AP shots were of a design as if someone designed them before ww1. Both guns on the M3 were a tad better in AP abilities than what the Churchill had. Churchill was the bulkier one, and was slower. It was also better armored.

Both Americans and British could've went with a gun of the power similar to what the pack howitzer had for installation in the turrets in the second half of 1930s, and move up from there.

Both tanks were retrograde. And no the American 37mm was not better than the 2pdr as a hole puncher. The US pack howitzer had some serious problems as a hole puncher. It makes the French short 75 look good.

Install a darned 6pdr gun as soon as 1935, if not earlier. Who cares if it is not as good as the historical 6pdr of ww2 fame.

The only 6pfr in existence that was better than the 2pdr was the 1920s costal defense gun and it was, unless extensively modified, not something you want to put in a 1930s tank turret.

his is one of the good reasons why people were trying to have their tanks shoot HE ammo, even if it was not of ideal size/weight - everyone's artillery in the 1930s was bad in following the tanks in the maneuvers the tanks of the day were capable of. The accompanying infantry will be also grateful to have the HE-capable tanks around them when advancing.

Very true, Finding out why the British screwed this up may be hidden in the official secrets act, only to be published after 300 years or some other strange rule

For my money, British making more and improved infantry tanks instead of the cruiser tanks is more than okay.

You don't get as many for your money and while they worked against some opponents

They didn't work as well against other, faster, ones.

 

[tomo pauk]

If so, everybody was installing guns that were passed their prime. A 9 prototype had one in 1936, production started in 1937, slowly, but that was not the fault of the 2pdr gun.
Who was installing anything better in 1937 in most of their tanks?
French were building how many 37mm armed tanks for every one with a 47mm or larger.

French and Soviets were installing the better stuff, while not forgetting the HE ammo for the 37-47mm guns.
The French were building dozens of tanks armed with the 47mm or/and the larger gun, with both guns being multi-purpose. Compares great vs. the British not making any multi-purpose gun. Any already by 1936.
We also have a thing of Somua 35 being manufactured in more copies than the A9, A10 and A11 combined.

Both tanks were retrograde. And no the American 37mm was not better than the 2pdr as a hole puncher. The US pack howitzer had some serious problems as a hole puncher. It makes the French short 75 look good.

At least in 1942, the US 37mm was a better hole puncher than the 2pdr, since the later was with the worse ammo. It (the 37mm) was also with the HE ammo, again something that the 2pdr lacked until too late.
The pack howitzer was a far better hole puncher than the 2pdr was a HE thrower.

You don't get as many for your money and while they worked against some opponents
They didn't work as well against other, faster, ones.

Infantry tanks were more than enough capable to to go toe to toe vs. the Axis tanks until the advent of the Pz-IIIJ and the Pz-IVF2/G. Infantry tanks were also more capable to go against the places the enemy had some artillery as a back up, or where the light AT guns were employed. Granted, not having the powerful guns was a shortcoming there.
FWIW, Germans have had some 12000 (12 thousand) of the 37mm pak by the time of invasion of France, as well as a few thousand infantry guns.

 

[Jimbob]

Yes, indeed.
Still not beating the French, though - the 3in howitzer was a very weak cannon.

 

[Jimbob]

From my collection

 

[Shortround6]

French and Soviets were installing the better stuff, while not forgetting the HE ammo for the 37-47mm guns.
The French were building dozens of tanks armed with the 47mm or/and the larger gun, with both guns being multi-purpose. Compares great vs. the British not making any multi-purpose gun. Any already by 1936.
We also have a thing of Somua 35 being manufactured in more copies than the A9, A10 and A11 combined.

Again we run into the timing problem, it takes several years to get guns approved and into production. Soviets were still testing the 45mm guns in 1937. French had approved the 47mm SA 35 in 1935, actually getting them into tanks took a while. The 47mm SA 34 (adapted antique naval gun) was better than a 37mm for throwing HE. For tank busting is was better than throwing snowballs.
The British had really screwed up the the lack of HE ammo. Still looking for the reason, a lot of passages in books about it being too small for effective HE. The British were the only nation on earth to think so. Everybody else who could buy or license 37mm infantry or AT guns was using HE ammo. Certainly far from ideal but no ammo is even further from ideal
The production numbers are a little skewed. The A11 was not in the same class.

Basically it was another mistake of British tank procurement. It was cheap and they got what they paid for. Not much as far as combat capability goes.
The thinking that a mobile machine gun (barely OK so far) was a good idea that could survive on the battle field by soaking up enemy AT gun hits with tough armor gets a little bit hard to swallow. Especially when it is slow (easy target), the crew can't see out well (figure out where the shells are coming from and dodge) and only has a machine gun to shoot back with (and most AT guns had bullet proof shield and were often dug in/emplaced).
A 9 and A 10 were judged to be not what was wanted even as they were being ordered. British British tank procurement was chaotic, to put it kindly. In the Spring of 1939 when the French had already delivered 192 Somua's the British were working on the initial design of the Covenanter which was to replace the A-13s (both types) and confusingly was also called the A13. British were slow putting tanks into production in the late 30s. French in 1939 had 4 basic chassis in production. British had around 6. and more in development.

At least in 1942, the US 37mm was a better hole puncher than the 2pdr, since the later was with the worse ammo. It (the 37mm) was also with the HE ammo, again something that the 2pdr lacked until too late.

American 37mm in 1938 was how good?
But you are correct, the Americans used better ammo in 1942. Both better AP and they used HE from the start. The British could have used better AP and HE from the start, they didn't.
But solving those problems by using a bigger gun in a bigger tank seems a little extreme. Solve the poor ammo problem while you work on the new, bigger tank.

The pack howitzer was a far better hole puncher than the 2pdr was a HE thrower.

True but without HEAT the pack howitzer was a rather dismal hole puncher. The 2nd part of using Low velocity guns for tank busting is the practical range is rather short. A 380m/s MV means a rather curved trajectory and a short point blank range. Hitting a tank at over 500yds gets difficult and you need more rounds to get on target and you have fewer rounds to get on target with. Rate of fire is a bit slower, especially if you had to go down to a two man turret crew to fit the bigger gun in the tank.

Infantry tanks were more than enough capable to to go toe to toe vs. the Axis tanks until the advent of the Pz-IIIJ and the Pz-IVF2/G. Infantry tanks were also more capable to go against the places the enemy had some artillery as a back up, or where the light AT guns were employed. Granted, not having the powerful guns was a shortcoming there.

Basically they screwed up. Jumping from 30-40mm armor to 65-78mm armor in order to go toe to toe means they never tried to build a tank with 40-50mm armor until too late.
Germans didn't build Light tanks (at least not many after 1940) or infantry tanks, or others (mostly, they got sucked into too many different designs but didn't field most of them) but the operational units had the small/medium gun medium tank (MK III) and the large gun support tank (MK IV) the MK III was supposed to do just about everything. There were a bunch of production issues that saw the continued production of MK IIs the 38(t).

FWIW, Germans have had some 12000 (12 thousand) of the 37mm pak by the time of invasion of France, as well as a few thousand infantry guns.

What fools those Germans were, Building over 12,000 37mm AT/infantry guns with useless HE ammunition
and building about 8,000 more by the end of the war, and licensing them to Italy, Japan, the Soviet Union and the US. All with HE ammo

 

[tomo pauk]

American 37mm in 1938 was how good?
But you are correct, the Americans used better ammo in 1942. Both better AP and they used HE from the start. The British could have used better AP and HE from the start, they didn't.
But solving those problems by using a bigger gun in a bigger tank seems a little extreme. Solve the poor ammo problem while you work on the new, bigger tank.

US 37mm with the initial ammo was indeed worse as a hole puncher.
British did go anyway with a very big tank at the time, adding another gun to toss around smoke shells.
I have nothing against making better ammo.

True but without HEAT the pack howitzer was a rather dismal hole puncher. The 2nd part of using Low velocity guns for tank busting is the practical range is rather short. A 380m/s MV means a rather curved trajectory and a short point blank range. Hitting a tank at over 500yds gets difficult and you need more rounds to get on target and you have fewer rounds to get on target with. Rate of fire is a bit slower, especially if you had to go down to a two man turret crew to fit the bigger gun in the tank.

At the shell weight of 6.5-7 kg shell at 380 m/s, the pack howitzer was an equivalent to the Kwk 37 as far as it gets. That one was managing the same MV, and it was good for 39mm at 30 deg at 500m, while the accuracy even under combat conditions was supposed to be very good.
Not to say that a better 75-76mm gun should not have been in pipeline before ww2.

 

[Shortround6]

I am reading several books about British tank development in the 1930s and WW II and I keep hitting passages about the ineffectiveness of the 2pdr and 6pdr HE ammo.
These do not line up well with the Production figures on this web site.

2 Pounder Anti-Tank Gun

2 Pounder Anti-Tank Gun - Design, Development, Production and Performance

www.wwiiequipment.com

Now the passages do not give dates except in very general terms. They never quote or refer to a test. They also never quote an actual report from a particular battle, such as "Sgt Tommy Thompson of Bertie Wooster Brigade said he fired 5 HE rounds at German AT gun to no effect and resorted to firing smoke grenade, moving and reengaging with Besa gun."
Lots of very general claims with no sources at all about the uselessness of the both the 2pdr and 6pdr ammo for several years except.....................

That website says, and could be wrong/incomplete data that in 1940-41-42 the British (and overseas) produced 18,449,000 2pdr AP rounds of all types and a just 40,000 rounds of HE for 461 rounds of AP for every HE round. If you don't have HE to fire it is certain to be ineffective. Given a typo and there were really 400,000 rounds manufactured in 1942 (at the factory does not mean at the battlefield) and you get 46 rounds of AP for every HE shell or 2-3 HE shells per tank. Some articles/books say the HE showed up in 1943 and was used in armored cars. In fact it is often stated that the armored cars which had been fitted with Little John muzzle devices (Squeeze bore) for better AP often left them off the barrels so they could fire HE when/if needed. Apparently the armored car crews did not think the HE was useless?

The 6pdr numbers are no where near as bad but one passage claims that the 6pdr HE was found to be nearly useless by the end of the Tunisian campaign.
Now in 1942 the production figures show about 20 rounds of AP for every HE round and for all of 1943 they show about 6.2 rounds of AP for every HE manufactured.
Just how many rounds of 6pdr HE did they use up in the Tunisia campaign? What was the load out for the tanks? 8 rounds of HE per Crusader or 6pdr Valentine ?
HE went to the towed AT guns?
A 6pdr HE round is certainly going to be much less impressive than the 75mm guns in the Grants and Shermans but near useless? Germans were firing off a fair amount of 5cm HE from their 5cm tank and AT guns.

Soviets must have been using better explosives in their 45mm tank and AT guns HE shells.