OK, here is a technical poser. Was it, or was it not, possible to fire 75mm US howitzer ammunition in the US M3/M2 75mm series tank guns? Gordon Rottman, a pretty well known WWII scholar, thinks it was: Tarawa on the Web Many months ago, I read an online account of a British tank crew in NWE who test-fired 75mm howitzer M66 HEAT ammo successfully in a Sherman. This might have some interesting implications, since the M66 round in question reportedly had better penetration (91mm or something like that) than standard M3 75mm gun AP. I don't have range/slope info on that 91mm figure, and I can't find good data for the M66 round at all. Even more unfortunately I have lost the reference to the British test. I think the unit that carried it out was 15th/18th Hussars, but I'm not sure. If anyone has more information or thoughts I'd like to hear from them.
Was there any other 75 mm US howitzers besides the Pack Howitzer used during WWII? I'm guessing that the pack howitzer ammo used a significantly different case than the 75 MM Sherman gun, which I think was a variant on the French 75. But I don't know any of the dimensions of either, so I'm just bloviating. Interesting topic, though.
A vehicle-mounted version of the 75mm [Pack] Howitzer was mounted on the HMC M8. From what I've got to hand, both the howitzer and the gun used the same HE shell - the M48 - but the cases were different [probably]. The guns used a fixed case, the howitzer used a semi-fixed case with adjustabe charge bags. A figure of 26.6" for the overall length of a fuzed gun round (M48 HE shell) looks slightly longer than the overall length of a howitzer round, but the latter is roughly scaled from a small drawing, so treat with suspicion. To sum up, the projectiles would be compatible, but the cases might not be. It's possible that the HEAT experiment involved mating the M66 HEAT projectile with a standard M3 gun case. I'll keep digging. A bit more: Wiki identifies the case for the 75mm Howitzer as "75mm Cartridge Case M5A1 (type II) and (type I)"; the HMSO Churchill book identifies the case fior the 75mm Gun as the M18.
Not the US 75mm howitzer HEAT round but .... IIRC the Germans issued plenty of HEAT ammo to the Pak 97 and those guns were modified French 75 Mle 1897 that fired a 75x350 round that was probably compatible with the M3 that was also derived from the Mle 1897. I don't recall seeing any Pak 97 in pictures from North Africa,though there were plenty of 76mm of Soviet origin, but some Sherman crew experimennting with that ammo in Italy or Normandy is likely.
Thanks, TiredOld. I presume you mean this gun: 7.5 cm Pak 97/38 - Wikipedia, the free encyclopedia Checking various references, the Pak 97/38 was apparently pretty common in Normandy, so it is likely that the Allies captured some ammunition for it.
