The final wartime revision of the Thompson Submachine Gun, the M1A1 was on paper made obsolete by the M3/M3A1, but would continue to serve as late as the Vietnam War. Blade front and fixed peep rear sights, with a horizontal handguard, "P" marked barrel, and an "AOC" marked machined receiver with "AO-45", "G.H.D." and "crossed cannons" on the left side of the receiver and "U.S. PROPERTY" on top behind the rear sight. The replacement/mismatched ("300718") trigger housing has dual control switches, a fixed buttstock, and a grooved pistol grip. Internals are M1A1 pattern, with a fixed firing pin on the bolt face, "P" on the left side of the bolt, "S" on the rear, "S" marked charging knob and recoil spring guide, and no provision for a Blish lock or oiler. The barrel has been internally threaded at the muzzle; traditionally, this modification is to permit the installation of a concealed restrictor block (not included) to produce enough back pressure with conventional blanks to cycle the action, often used for cinematic purposes or reenactor demonstrations

Fine as assembled (see above), with 85% plus arsenal refurbished parkerized finish, showing areas of gray patina, edge wear, and minor handling marks and spotting overall. Some dings are present on the front sight and rear sight protector. The furniture is very good, with light dents and scratches overall and some hairline cracking in the pistol grip. Mechanically excellent. NOTE: This weapon is a National Firearms Act (NFA), fully transferable Class 3, which is registered with the Bureau of Alcohol, Tobacco, Firearms and Explosives, (BATFE) that is classified as a "Curios or Relic" as defined in 27 CFR, 478.11. These weapons are still subject to the provisions of 18 U.S.C. Chapter 44 and 27 CFR part 479.