Developed circa 1941-1942 in response to the British STEN gun, as a substitute for the M1 Thompson SMG which could be produced faster and more efficiently, the "A1" variant was introduced in 1944. Though withdrawn from overall service in 1957, the M3A1 was still issued to vehicle crews as late as the First Gulf War. Fixed blade front and peep rear sights, with a Korean War-era M9 flash hider secured to the muzzle. The magazine well bears the Guide Lamp marking over "crossed cannons/ U S NO 615650", with black felt lining inside the dust cover/ safety, and the proper cocking notch at the front of the bolt. A checkered pattern is tamped in the grip section, with serrations on the rear of the wire buttstock.

Professionally refurbished, with 99% of the matte gray finish, showing a few tiny areas of pitting below the surface, and minimal handling marks. Mechanically excellent. NOTE: This is a fully automatic firearm, registered with the Bureau of Alcohol, Tobacco, Firearms & Explosives as a Class III Weapon, "LIMITED TO USE AS A SALES SAMPLE", and it is the sole obligation of the bidder to understand and comply with all laws and restrictions which apply in their place of residence.