More properly known as the M3 submachine gun, the M3 “grease gun” was a .45-caliber SMG made from stamped steel parts and issued to US troops in WWII because it was cheaper to mass produce than the Thompson SMG. A variant, the M3A1, saw service in Korea where it was one of the main SMG platforms carried by American and South Korean soldiers. Because of its compact design, it could be issued to tank crews; it also proved more reliable than then Thompson even when it was not kept thoroughly clean. Explore a wide range of M3 grease gun parts here (and parts for the M3A1) as well as M3 grease gun accessories, like cases and mag pouches, and if you have questions, get in touch with us.