Colt Firearms manufactured approximately 15,000 Model 1921 Thompson Submachine Guns for the Auto-Ordnance Corporation in 1921. They originally had a cyclic rate of 800 round per minute and were not fitted with Cutts compensators. Between 1926 and 1928, the Marine Corps obtained a few Model 1921 Thompsons, and based on their combat experience in Nicaragua and China, they recommended a reduction in the rate of fire to a more manageable level. In response to the Marines, the Auto-Ordnance Corp. modified the design to reduce the rate of fire to approximately 600 rounds per minute and added a Cutts compensator to reduce muzzle rise during firing. In 1928, Auto-Ordnance redesignated/remarked the modified 1921 guns as "Model 1928" and stamped "U.S. NAVY" over the original "MODEL OF 1921" markings. The left side of the receiver is now stamped with an "8" over the "1" in "1921". Although the guns were marked "U.S. NAVY", most Model 1928 Thompsons were sold to law enforcement, as in this case. The left side of the trigger frame has the second style "FULL/AUTO", "SINGLE" and "FIRE-SAFE" markings found on most Colt/AO Model 1928 guns. The left side of the receiver is stamped with the serial number "NO 11204", with "MC 5209" etched below the serial number followed by the following five lines: "THOMPSON SUBMACHINE GUN/CALIBRE .45 AUTOMATIC COLT CARTRIDGE/MANUFACTURED BY/COLT'S PATENT FIRE ARMS MFG. CO./HARTFORD, CONN., U.S.A." The right side is roll-stamped: "AUTO-ORDNANCE CORPORATION./NEW YORK, U.S.A." followed by the six-line block of patent dates. The top of the receiver is stamped with the Thompson "Bullet" trademark. The bottom of the trigger frame is stamped with the matching serial number "NO 11204". This example has the second model Cutts compensator with Cutts trademarks and patent markings on the top. The side of the walnut buttstock is branded "MULT. CO.", which stands for the Multnomah County Sheriffs Office of Portland, Oregon, and the forearm and pistol grip appear to be original Colt/AO components. The gun has the 1928 internal components which include: (1) a 1928 second style blued weighted actuator, (2) long one piece pilot rod. (3) small diameter recoil spring. The gun has the original finned barrel, vertical walnut fore-grip and folding Lyman leaf rear sight marked. The internal components on the trigger frame and stock are finished bright. This lot includes an original FBI style storage case wit the blue felt lining, one Thompson 50 round, "L" marked, WWII Auto-Ordnance drum magazine, six Auto-Ordnance marked 20-round magazines, all with the later three line patent dates and the large ring brass cleaning rod.

Very fine condition with 85% of the original blue finish overall showing wear and blue loss on the sides of the receiver with some heavier wrench/handling marks around the compensator when it was screwed on to the barrel. The markings are still clear and distinct. The wood components are all in very fine condition with a nice medium brown matching color overall showing handling marks and some light scratches from actual use. Mechanically excellent. NOTE: This item is restricted as 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 478.