Firing US 75mm Pack Howitzer Ammunition from M4A2 Tanks on Tarawa in WWII

[M8owner]

In the book "Tanks in Hell: A Marine Corps Tank Company on Tarawa", the author talks about how the medium tank company that landed (a light tank company landed also) ran out of 75mm ammunition for the tank guns because the tanks were logistical orphans in the battle - one the lessons learned. He says they fired pack howitzer ammo because that is all that was available. As most of you know, the M5 or M5A1 cases for the pack howitzer are much shorter than the M18 75mm cases for the tanks. The pack howitzer ammo is semi fixed also, but the high explosive shells are the same - the M48. He says "They did not load the same, and they did not shoot the same, but they worked." I have compared my M5 and M18 cases, I believe the base diameters and rim dimensions are the same, so the M5 case would obturate and seal the breech of the gun when firing. So this seems completely truthful and accurate to me. The only exception would be that the need to load the case and the projectile separately into the gun. What are your thoughts?

 

[Gspragge]

Clearly this would work and of course they would have to separate load (or have bad accidents), but naturally they would have to adjust to a new shorter trajectory. And if he said they had to resort to this then it was done. Certainly the gunners would have told them what they had to do in loading them. Seems a quick solution to a bad problem, it's just fortunate that a number of factors lined up well enough to have it work.

 

[Tony Williams]

I have heard of this before and I agree, I see no reason why it would not work.

In fact I am surprised that the howitzer case was only about three inches shorter than the tank case, given the difference in performance.