This Colt/Auto-Ordnance Model 1928 Navy Thompson Submachine Gun was manufactured in 1921 and is listed by serial number in Herigstad's "Colt Thompson Submachine Gun Serial Numbers and Histories" as being delivered to the Carbondale, Pennsylvania Police Department (page 1006). Colt Firearms manufactured 15,000 Thompson Submachine Guns for the Auto-Ordnance Corporation in 1921. All 15,000 Colt/AO Thompson Submachine Guns were originally designated Model 1921. The Model 1921 Thompson Submachineguns had a 800 round per minute rate of fire and were not fitted with Cutts compensators. Between 1926 and 1928, the Marine Corps obtained a few Model 1921 Thompsons. Based on combat experience in Nicaragua and China, the Marines recommended reduction of the rate of fire. In response to the Marine critique of the Model 1921, Auto-Ordnance modified the bolt, recoil spring and pilot rod to reduce the rate of fire to around 600 rounds per minute and added a Cutts compensator to the muzzle to reduce barrel climb during automatic fire. In 1928, Auto-Ordnance designated modified guns as "Model 1928". The modified Thompsons had "U.S. NAVY" stamped above the "MODEL OF 1921" marking on the left side of the receiver and "8" hand-stamped over the "1" in "1921". Although the guns were marked "U.S. NAVY", most Model 1928 Thompsons were sold to law enforcement. This gun has the larger, second style, Cutts compensator with Cutts trademarks and patent markings on the top. 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 and (4) red fiber recoil buffer. The bronze Blish lock is correctly not stamped with sub-contract marks. The bolt is bright and has a "C" stamped on the inside. The gun has the original finned barrel and folding leaf rear sight marked: "MADE BY 'LYMAN' MIDDLEFIELD, CONN. U.S.A." on the base. The internal components on the trigger frame and stock are finished bright. The front of the detachable stock is stamped with the small anchor symbol used by the stock-maker Remington Arms. The forearm and pistol grip are original Colt/AO components. The ejector, magazine release, firing lever and safety are all the early Colt/AO components. 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. In addition to the model markings and the serial number "NO 12666", the left side of the receiver is roll-stamped: "THOMPSON SUBMACHINE GUN/CALIBRE .45 AUTOMATIC COLT CARTRIDGE/MANUFACTURED BY/COLT'S PATENT FIRE ARMS MFG. CO./HARTFORD, CONN., U.S.A." in five lines below the rear sight. The right side of the receiver is roll-stamped: "AUTO-ORDNANCE CORPORATION./NEW YORK. U.S.A." in two lines followed by the six-line block of patent dates. An encircled "JHB" monogram utilized by Auto-Ordnance inspector John Barrett is lightly stamped ahead of the patent marking. The top of the receiver is roll-stamped with the distinctive Thompson "Bullet" trademark. The bottom of the trigger frame is stamped with the serial number "NO 12666". The trigger frame and receiver serial numbers match. Included with this Thompson are: (1) a 50 round "L" WWII Auto-Ordnance drum magazine, (2) two early Colt/AO 20-round magazines with two-line 1920 and 1921 patent dates and (3) a nickel-plated oiler. The gun has a BATF Form 4 and is a registered Class III weapon.