Help identifying 75mm exploded shell - strange base?

This looks like a WW1 French or American 75mm artillery shell. It measures correctly and the surface in the driving band groove is right. However, the convex cap or plate on the butt doesn’t look familiar to me. I can’t tell if it is original to the shell or something added…why, I would have no idea.
Any ideas as to the identity of this?

1 Like

The convex plate on the base is probably a gas check plate that has become distorted when the shell detonated. Does appear to be a bit small, however I’m not familiar with non-British artillery projectiles.

The purpose of the gas-check plate is to protect possible fissures in the cast projectile body against being penetrated by the propellant gases. Such an event could trigger in-bore detonation of the explosives charge.
Like TimG I consider the plate a little small compared to what is usually seen on German projectiles. But I think it is the most probable explanation.

Would it be possible to get a picture of the interior of the round? Thanks, Bruce.

Here is the interior…

Thanks, SKELLY. The only thing I can think of is that it was an early attempt at a base plate before they increased the diameter of them. That diameter seems to only cover the inside diameter of the forging, and the machining to create the caulking well would just make that portion thinner to what they were trying to prevent, gas penetration, or as a discussion on BOCN refers to it, “piping”. Later 75mm rounds have a base plate that goes to about a half or 3/8" from the rim. My guess is that this would allow the caulking well to be in (1) a thicker area of the body not adjacent to the inside forging, and (2) Allow for more of the base to be protected from gassing. All this is supposition, but I think sound without documentation. Thanks for showing. Also, the base plate seems to be either copper or brass. Could you confirm which? Thanks, Bruce.

1 Like

It appears to be copper. Would you offer an idea of the age and nationality? I was thinking French…perhaps pre to very early WWI?

Skelly, the knuraling for the band seat looks like all of the ones I’ve seen on US 75mm rounds. I don’t know if the French used base plates.

Thank you for your input. Really appreciate it. I agree…I have seen that surfacing on a few shells that were confirmed to be US made. This came from England, thus it was probably found in Europe. Could that point to it being US made and used by US or French gun crews during the war…or would its gas-check design be far too early for WWI?

Skelly, I’m fairly positive that it would have been WWI and used by US Troops. The US was using the 3" FG right before, but found itself short of them. I don’t recall having seen a base plate on a 3" FG round, and have been at several Pre to WWI US Training Ranges that fired both the 3" and 75mm FG’s where we located a great deal of both.

France was producing the M1897 75mm FG’s enough to equip us with them, and I know we did produce the M1897’s also, just don’t know if we were doing it before our involvement, but I think we were. I know for sure we were producing the 75mm ammunition beforehand. It was our standard FG up till WWII, using both the French and the US model well into WWII, re-mounting them on the M2 Carriage and the Gun Motor Carriage M3 (half track) had an M1897 FG.

It seems to me your shell is a transitional piece of history.

Thanks for all of your info. I am a WWI uniform and equipment collector. But, I wanted an example of a an exploded shell in my display. This gives me some confidence that I have an accurate representation. Best Wishes.