37-mm M4 performance

[Greyman]

I'm trying to paint a more complete picture of what the gun/ammunition was capable of, and was wondering if anyone had anything to add.

Pendine Penetration Trials
37-mm M51 AP, without cap, air service cartridge case

35mm at 400 yards 0 degrees​

30mm at 400 yards 30 degrees​

Pendine Penetration Trials, homogeneous armour plate
37-mm AP, 1650 f/s, 350 f/s aircraft speed

38mm at 400 yards 10 degrees​

34mm at 400 yards 30 degrees​

​

British Trials (Pendine?) accompanying text seems to indicate these are more definitive than previous trials
37-mm AP 1650 f/s

28mm at 400 yards 0 degrees​

27mm at 400 yards 20 degrees​

37-mm AP 1650 f/s + 350 f/s aircraft speed

38mm at 400 yards 0 degrees​

36mm at 400 yards 20 degrees​

USAAF Experimental Establishment, Elgin Field
37-mm M80 AP, 1650 fps, P.39D (240 mph)

38.1mm at 400 yards 0 degrees​

Standard Ordnance Items, Chief of Ordnance Technical Division, 1944
37-mm M80 AP, 1825 fps

25.40mm at 500 yards 20 degrees (homog plate)​

15.24mm at 1000 yards 20 degrees (homog plate)​

20.32mm at 500 yards 20 degrees (fh plate)​

10.16mm at 1000 yards 20 degrees (fh plate)​

 

[P-39 Expert]

One hit and bye bye.

 

[wuzak]

One hit and bye bye.

If you can get a hit.

 

[Elvis]

Would be cool to see the effect of popping off a few rounds, from the pilots POV, while in flight.

 

[P-39 Expert]

Would be cool to see the effect of popping off a few rounds, from the pilots POV, while in flight.

In New Guinea early in the war procedure was to fire a couple of rounds before combat to make sure it was working properly and new pilots were often startled when they saw explosions ahead of them. It was their own test rounds exploding after the magnesium flare used as a red tracer for each round burned off and detonated the round. "Ack-Ack" they would scream into their microphones. Their more experienced flght leader would reply "Those are your own shells, lamebrain".