Drawing inspiration from the British STEN gun, the M3 was developed as a high-speed, low-cost substitute for the Thompson family of submachine guns. While lacking the aesthetic charm of the Thompson, the M3 was a serviceable weapon and would be America's go-to SMG through World War II and following conflicts. The A1 variant further simplified the design, eliminating the ratcheting cocking lever in favor of the operator cocking the bolt by hand, along with other improvements to reduce weight, improve reliability, and make maintenance easier. Blade front and peep rear sights, with the model nomenclature and Guide Lamp markings on the left side of the magazine well, integral oiler in the pistol grip, the combination dust cover and safety on top and a telescoping buttstock, which doubles as a magazine loading tool and barrel bushing wrench. One unmarked magazine is included.

Very fine, showing 85% plus matte gray phosphate finish, with some scuffing, a few spots of brown patina, and what appears to be some sticker residue. The nomenclature and "crossed cannon" stamps on the magazine well are faded, and the trigger housing assembly bears markings from Inter-American Arms of Sacramento, California. Mechanically very good. NOTE: This weapon is a restricted, National Firearms Act (NFA) Class 3, Fully Automatic Weapon, that 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. This weapon is currently registered as being "LIMITED TO USE AS A SALES SAMPLE (Pre-86)" and as such can only be purchased by an FFL, with a Class 2 or Class 3 SOT License.