Shooting the M3A1 Grease Gun

The M3 (and its followup improved M3A1 model) was the United States’ answer to the high cost and manufacturing complexity of the Thompson submachine gun. The M3 “Grease Gun” (because really, that is what it looks like) was a very inexpensive weapon with a stamped and welded receiver and only a fed milled parts. It also had the slowest rate of fire of any World War 2 submachine gun at about 450 rounds/minute. Its weight, compactness, and controllability made it almost universally preferred over the Thompson, at least by soldiers who had to carry and fight with either of them.

The Grease Gun is reputedly extremely controllable because of its low rate of fire, but this is my first time to actually try shooting one. Will it live up to that reputation?


  1. “Get your ugly mug out of my truck!” I suppose that could happen if any Axis holdout ever jumped into an American supply truck in the hopes of taking all the goods out of it after tangling with the driver. The M1 carbine also served to keep would-be carjackers at bay, unless I have messed up…

  2. This video took me back to my days in Germany (66-68). We worked on a lot of M3-A1’s. Most of the problems were with the little spring that kept the barrel from rotating. The tankers seemed to have heavy thumbs and broke or loosened them. Otherwise a very servicable weapon. The “shooters” always seemed to hang around the small arms shop and back then the drill instructors in basic training would always produce a coin and place it on the wings of the front sight and would pull the trigger without jarring the coin off. Usually at some point in our conversations someone would brag that they could do it with any gun. Bets were made and out would come the M3. Much time was spent looking for the coins after the heavy bolt slammed down. I only got to shoot one once at the Aberdeen Proving Grounds.

  3. M3A1 Grease Gun submachine gun was preferred as opposed to carrying the Thompson machine gun…but the early magazines for the M-3 Grease gun seem to have been lacking in quality control…heard this from maybe 20 WW II 82nd AB troopers…

    at least, so I was told by a VN Era vet of 82nd AB, Ranger, Special Forces…but preferred much more was the M-2 .30 Caliber Carbine…much more ammo could be carried for a given weight package.

    • The .30 Carbine had better performance and penetration at medium range than .45 ACP. By medium I mean 100-200 yards away. So much for using trees as cover…

      • At 300 yards, the .30 Carbine’s bullet still has about the KE of either the .45 ACP or 9 x 19mm slugs at the muzzle of an SMG. (Energy for both rounds is a bit higher from the SMG than a pistol due to longer barrels and somewhat higher MV.)

        It’s also more accurate and kicks less, even in an M2 on full-auto.

        In Korea, it was found that in any “duel” between U.S. infantry with carbines and the other side with 7.62 x 25mm SMGS, the Americans generally won.

        With all of that, I’ve never quite understood why the Carbine is considered “obsolete”. If anything, it rendered every SMG in existence obsolescent when it was introduced in 1941.



  4. I like an alternative nickname: the Enema Syringe.

    I remember some 4th of July parades in my childhood wherein some of the National Guardsmen marching in the parade were carrying M3’s.

  5. I love the line in the movie “Fury”- “Boys, walk him through that gun”- “you see that cover” “open it” “Now you’re killin” “Close it” “now you ain’t”

  6. Everyone here probably knows this, but these were used by the US Military up into the 1990’s. Vehicle crews and even some MP’s I think. They were also in some National Guard armories.

    Presumably this gun was made legal during an amnesty after being stolen from Uncle Sam at some point. Who knows, might be a battlefield pick up shoved into a duffel bag coming back from Korea. Might be what Ian was alluding to in how rare they are on the civilian market.

    • M3A1s were part of the standard kit for M1 Abrams tank crews in Desert Storm just as they had been for MBT crews from 1945 on. Mainly because it was about the only IW bigger than a pistol that could be accommodated inside a tank.

      As for their rarity, it has less to do with Federal law than simple mechanics. By the time the Grease Guns were officially retired in 1993, most of them were really only fit to be scrapped due to wear. People forget that production only ran from 1945 to 1953, and everything after that was a rebuild.



    • I doubt it was stolen. Most of the transferrable M3’s are reactivated registered dewats. Prior to 1968, one could buy, by mail, a deactivated machine gun. Deactivated M3’s were sold in magazine ads in Field and Stream and others. Dewats were required to be registered in 1968, and as they are registered as machine guns, can be legally reactivated.

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