Monday, 8 April 2013

American Guns vs German Tanks

The 1942 "Report on the shooting of German tanks with AP and HE shells from tank guns" contains testing of American guns against captured German tanks: the 37 mm M5 tank guns on the Lee and Stuart, and the 75 mm M3 gun on the Lee.
The first test subject is the Czech LT vz 38, also known as Pz 38(t). The first tank to shoot at it is the M3 Stuart, firing M-51 shells out of its 37 mm gun.

The first target is the front armour plate. At 50 and 100 meters, only one shell out of 5 fails to penetrate. Holes made in the armour are noticeably larger than the shell caliber (70-80 mm in one dimension). Next target is the turret platform. One shot at 400 meters, and one shot at 600, both penetrate. Next is the side of the turret, at 800 meters. Again, all penetrations. The second shot to the right side of the turret caused a crack 140 mm long. The final shot is at the front of the tank, at 100 meters. It strikes the MG, and knocks it out. 

Conclusions: "Front armour, 50 mm thick can be penetrated starting at 100 meters. Sides of the tank, 30 mm  thick, can be penetrated at 800-1000 meters."

Regrettably, the photo quality isn't fantastic, but you can see that, in the top photo, the MG ball was knocked out. The second photo shows the shells extracted from the tank. Like all American shells, they mostly retain their shape, even after penetrating armour. 

That's it for the vz 38. The armour plates are overly hardened, as we've seen on the mid-late war German vehicles. This causes the plates to crack, spall, and fall off.

Next up for testing is the StuG. The 37 mm American gun, once again, gets first dibs.

Shots at 100 meters at the front plate. All 3 go through, one shot damaging the braking mechanism. The Germans' early war armour is ductile, giving breaches not much larger than 37 mm in diameter. The next three shots are fired from 150 meters. All fail to penetrate the armour, making dents. Another shot is fired at the side, from 800 meters, penetrating the gas tank. 

The top photo shows the StuG after taking a penetrating hit from the side. The bottom photo shows the shells. Shells marked 1 were the ones that penetrated the hull. The shell marked 2 was one of the shells fired from 150 meters that did not penetrate.

It's the Lee's turn next, firing HE shells from its 75 mm gun. 

The first shot, from a distance of 800 meters, hits the front armour. The 50 mm thick plate shows no signs of damage. The 30 mm thick cover of the transmission is dented 8 mm down, and the welding seam suffers a rupture 80 cm in length. The right half of the transmission hatch is torn off. Subsequent shots are fired at the side of the StuG.

The second shot, also at 800 meters, hits a wheel, damaging it. A second shot tears off the rubber tire. Even after two direct hits, the wheel is still functional. A shot to the side leaves a negligible mark on the armour and damages the gas mask holder on the inside. A torsion bar carrier is torn off. 

Closing in to 600 meters, the Lee shoots at the radio bay. The armour plate is bent inwards 8 mm. A crack forms along the welding seam, 1.5 meters in length.   

Further shots from 600, 500, and 400 meters keep slightly bending the armour, damage 3 track links, and a roller. 

Conclusion: "The 75 mm HE shell from the M-3 Medium tank does not penetrate or destroy a StuG from 800, 600, or 400 meters."

This is it for American guns in this report. Here are the applicable conclusions:

"The 37 mm American shell, after penetrating 50 mm or armour at 100 meters, shatters into 3-5 fragments. The tip of the shell is usually intact. At 150 meters, the shell usually makes a dent 40-50 mm in a 50 mm armour plate and breaks into 3-5 fragments.
Scattering of shells from the 37 mm and 40 mm guns does not exceed the size of a StuG at 800 meters.
Of all the gun sights tested, the American gun sight on the M3 Light and M3 Medium led to the worst accuracy.  
Of all low caliber shells, the American 37 mm shell is of the highest quality, and provides the most penetration. "

Another report also tests the Sherman's gun against the Tiger, which I covered earlier.

The American M1A1 76 mm gun, mounted on an M18 Hellcat (serving in the Red Army under the name T-70 Ved'ma, or Witch) was tested against a Tiger II. Firing M-62 APC shells, it achieves the following results: 

"The armour piercing shell of the American 76 mm gun penetrates:
  • The side of the hull at 2000 meters.
  • The overtrack hull at 1500 meters.
  • The turret side from 1500 meters."


  1. How about any tests of shelling M4 itself, done in USSR?

    1. Almost certainly. I will post them if I ever see them.

  2. The 75mm HE shells sent with the Lees may have been the very aged stock left over from WWI and immediately afterwards. These were supplied to the British early on because new production was inadequate and the U.S. Army desperately wanted to build up its own stocks.

    If so, the propellant had degraded, so the actual ballistics didn't match the gunsights. I believe that the explosives had probably degraded as well, so with the combination of lower imapact velocity and lower explosive propagation, it's possible that the anti-armor (and anti-track) effects were far less than they should have been with fresh rounds.

    The problems were bad enough that in North Africa, the British removed the projectiles from the cases as they arrived, dumped out the propellant, and replaced it with fresh propellant ...

    So, not trying to be nationalistic here because a lot of the ammunition that the U.S. supplied early in the war was crap, and it's hard to understand how the slightly heavier American HE shell with with either slightly less explosive filler, or considerably more filler, could be so much less effective.

    I'll throw out one other possibility: someone set the fuses to delay (0.15s) instead of super-quick (0.05s). That seems unlikely, but if I told you about some of the screw-ups around here, you literally wouldn't believe me.