Artillery shell ID

Hello, I was hoping someone could help me id an old artillery shell that I found. Its aprox. 15 inches tall, appears to be recoiless due to the porting(or holes all around the casing) it tapers at the top to hold the bullet and it has markings on the bottom of the base: AMM.LOT J A-3-1 7A and also: CTG. M309A1. Any information would be helpful. thanks- Brian Paul

From the markings and description, you’ve got a fired cartridge case for the M20 75mm Recoilless Rifle (the M309A1 is the descriptor for the HE/high explosive round); see for a picture of the rifle.

thanks sdc, is there anyway to find out when it was used? by the amm.lot number perhaps? I found this in my grandpa’s basement and he was in the pacific area during wwII.

I honestly doubt it; these were in inventory during the time of the Korean War, but were fairly quickly replaced by the 105mm Recoilless and the 3.5 inch bazooka; I’ve got no idea how long they stayed in secondary or training use. The only ones who could date that case by the lot numbers probably don’t even have the records anymore.

You certainly mean the 106mm recoilless M40 since the 105mm was rather scarce. (by the way, does anybody have more info on the 105mm rcl. itself and the ammo? If I remember correct it was in service with the home guard or so?)
Actually the 75mm and the even older 57mm were still in service during the Vietnam war - at least with the US allies which were supplied by the US. There I have even seen ammo dating from 1945.
Not to forget that there was also a 90mm recoilles gun which also saw service in Vietnam (think it was smooth bore).

I believe some of the 75mm recoilless rifles and 105mm recoilless rifles have been used for avalanche control purposes until recent years, drawing on surplus military ammo stockpiles. It is just as possible that the case came from a mundane use like that as from some heroic conflict, or routine training situation, or off a table at a local gun show.