Shooting a M3A1 Grease Gun

The U.S. Submachine Gun, Cal. .45, M3A1, affectionately called the “grease gun“ for its resemblance, was adopted in December of 1944. It has a simplified cocking mechanism of a finger notch machined in the bolt used for cocking rather than a lever. Chambered for the .45 ACP cartridge, it uses a blowback design and fires from the open bolt with a rather slow 450 rounds per minute rate of fire, making it very controllable. The M3A1 remained in U.S. inventories and was issued until the 1990’s. For more information on historic firearms, head on over to If you like the History In Firearms content, please consider supporting us on Patreon. All funds go to expanding and improving content from the project.