US 37 mm ammo after WW2


After WW2 the US engaged in lots of experimental cannon designs, in calibres up to 37 mm.

One of these 37mm guns is quite well known - the T250 rotary gun for the Vigilante T249 AA system, which seems to have started with 37 x 256 ammunition (T250X-1) then changed to 37 x 219 (T250X-2) - was the second of these cartridges designated the T68 or was that just the case?.

There were two earlier guns, however: the T37 recoil-operated single-barrel gun, which was later redesignated the T171E2. The other was the T172E1 revolver cannon. The only info I have on the ammo for these guns follows: “The T172E1 gun was to fire the same [electric primed] ammunition as the T37E2, namely the T181 or T324 37 mm high explosive shell”.

I would be very grateful for any clarification concerning the ammo used in these guns!


Bob Mellichamp would know. I have not heard anything about him in quite a while, and I hope that his definitive work on 37mm ammunition is ready for the third volume by now. The hurricane in Houston may have been a disaster for him, but I hope not.


Good thinking - I’ll drop Bob a line.

I’ve noticed a typo - it should read: “the T37 recoil-operated single-barrel gun, which was later redesignated the T172E2. The other was the T172E1 revolver cannon”


I’ve tried sending a message to Bob, but the address I have no longer seems to work.

Does anyone have a current email address for Bob, and if so could you send me a private message please?


From the Military Guns and Ammunition Forum, hosted by Tony Williams:

37 x 219mmSR, 37-mm T324-E22 Shell, report from 1957

DTIC_AD0156717.pdf (4.0 MB)


Thanks for this, the document links the T324 shell designation to the Vigilante ammo (it was also used in the T172 guns mention in the OP). However, I think that the T172 projects came some years before the Vigilante programme, so I’ve still not found anything which definitely identifies the T172 ammo. I think it was probably based on the 37x223SR M1 AA gun ammo, though.