Wednesday, 10 April 2013

British Guns vs German Tanks

Since large amounts of British and American Lend-Lease vehicles were shipped to the Soviet Union, it was important to know how well they perform against German tanks. The 1942 "Report on the shooting of German tanks with AP and HE shells from tank guns" (CAMD RF 38-11355-832) tests the 40 mm QF 2-pounder gun on the Valentine MkIII.

First up for the test was the Czech LT vz 38, used by the German Wehrmacht under the designation PzKpfw 38(t).

At 250 meters, the 2-pounder penetrates the first 25 mm plate of the front armour, but does not penetrate the second. The front plate develops a crack 250 mm long. At 400 meters, it can only form a 7 mm deep dent in the first armour plate. Closing in to 200 meters, the Valentine fires at the front plate of the turret platform and penetrates. A hole is formed, 50 mm in radius. Cracks run though the first armour plate, 200 mm around the breach. 5 bolts holding the front armour plate in place are torn off. Firing again, from 600 meters, the shot forms a crack from the top to the bottom of the front armour plate. 

Moving on to the side, the first shot penetrates the turret all the way through. One hole on the left side, 55 mm entrance diameter, 70 mm exit diameter. One hole on the right side, 38 mm entrance and 38 mm exit diameter. Another shot at 600 penetrates the turret, and also the ammunition rack of the tank. 

At 800 meters, the Valentine penetrates the side of the turret, forming two cracks, 600 and 400 mm long. 10 bolts holding the armour plate on are torn off. Another shot from 800 meters penetrates the side of the turret platform, forming two 300 mm cracks, and causing spalling. 

Moving to the front of the tank again, the Valentine fires a shot at the upper sloped plate at 400 meters. A section of the armour, 300 mm by 140 mm, is broken off. Another shot at the lower sloped plate breaks off a piece 100 mm by 150 mm and penetrates the gas tank.

Conclusions: "The 40 mm AP shell does not penetrate front armour 50 (25+25) mm thick. The reason for this is poor quality of the shells. They are destroyed completely on impact.
The 30 mm side armour can be penetrated from 800-1000 meters."

That's it for the vz 38. The armour plates are overly hardened, as we've seen on the Tiger II. This causes the plates to crack, spall, and fall off. Still, the front 50 mm of armour prove to be a challenging opponent for the 2-pounder at any distance. 

Next up for testing is the StuG III. At 50 meters, the 2-pounder only forms a 20 mm deep dent in the StuG's front armour. However, at 100 meters, it manages to penetrate the upper part of the front plate. That result does not repeat, as another shot from 100 meters only makes a 25 mm deep dent. 4 shots from the side, all at 850 meters, go through.

Conclusion: "The 40 mm tank gun penetrates the side of the hull, 30 mm thick, from 850 meters. The front of the hull, 50 mm thick, is not reliably penetrable at any distance due to the poor shell quality. Upon impact, the shells shatter into small fragments."

The Valentine gets another turn, this time against a PzIII. The results are similar to the StuG. It cannot penetrate the front at 100, or even 50, meters. 

In the conclusions, the following is noted: "The British 40 mm shell, when fired at a 50 mm armour plate from 50-100 meters, makes a 20-25 mm dent and shatters. " ... "Scattering of shells from the 37 mm and 40 mm guns does not exceed the size of a StuG at 800 meters."

Quite a poor showing by the country that invented tanks in the first place! Let's see how their larger gun fares. Another test pits the 6-pounder from the Churchill MkIV against the Tiger.

"Target: turret. Armour thickness: 82 mm. Distance: 800 m. Result: penetration. Entrance hole 82 mm in diameter, exit hole, 75 mm in diameter

Target: turret. Armour thickness: 82 mm. Distance: 1000 m. Result: dent 90 mm deep, 90 mm in diameter. Inside, a 10 mm bump is formed, with a crack.

CAMD RF 38-11377-12

Target: turret. Armour thickness: 82 mm. Distance: 1000 m. Result: dent 120 mm by 80 mm, 70 mm deep. Bump on the inside.

Target: side. Armour thickness: 82 mm. Distance: 1000 m. Result: penetration, entrance hole 70 mm in diameter, exit hole 115 mm in diameter.

CAMD RF 38-11377-12

Target: side. Armour thickness: 82 mm. Distance: 625 meters. Result: penetration, breach diameter 58 mm.

Target: side. Armour thickness: 82 mm. Distance: 625 meters. Result: unsatisfactory hit on the bottom of the armour plate."

There's a comeback! Gone is the poor shell quality of the 2-pounder. Instead of shattering into dust on impact, the 6-pounder penetrates German armour at a great distance. The armour, on the other hand, is worse than what we saw on the StuG, with cracking and large diameter holes. 


2 comments:

  1. Am I missing something here? Because I don't see any cracking here aside from the one mention of a "crack" in the Tiger test (and of course the 38(t) test).

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  2. The interpretation of poor armour is misleading, at best. No cracks, nor plugs are visible, indicating tough armour plate. The raised diameter is indicative for defects in the projectile during penetration attempt, f.e. mushrooming/ bending / upset.
    These defects were frequently encountered in early and mid ww2 ammunition. 6pdr AP improved in quality during manufacture by adopting higher alloy steel, suitable to ideal hardening.

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