Originally developed in the 1940s (with this example produced in the 1960s/1970s), the M1A1 was the war expedient version of the famous Thompson SMG. Stripping away most of the cosmetic and mechanical bells and whistles, the M1A1 still retained the distinct profile and "heavy metal" construction of the famous Thompson, and held a reputation for ruggedness and reliability. While in theory rendered obsolete by the M3 "Grease Gun", the M1A1s in American inventory are known to have been in service as late as the Vietnam War. Fixed blade front and peep rear sights, with an unribbed barrel, straight handguard, and the Thompson/Auto-Ordnance marked receiver fitted with a side-cocking, simplified bolt. The trigger group is numbered "512464" on the underside, with "FIRE"/"SAFE" and "FULL/AUTO"/"SINGLE" control levers and a fixed buttstock with a trapdoor buttplate. Included with the item is a green canvas soft case, numbered "8300-442650" on the back.

Excellent, with 98% of the parkerized finish, with a small amount of covered pitting present on the trigger housing and some small parts. The rear sight is a bit loose. The wood is in very good condition, with some light dents and scratches. The case shows some wear and staining, and appears to be missing a shoulder strap. Mechanically excellent. NOTE: This weapon is a National Firearms Act (NFA), Class 3, which is registered with the Bureau of Alcohol, Tobacco, Firearms and Explosives, (BATFE) under the provisions of 18 U.S.C. Chapter 44 and 27 CFR part 478.