Mar 27, 2011 Thompson Serial Numbers - posted in Thompson Submachine Gun. Be numbered 134,XXX unless they started a new AO serial number block. Same applies to the M1/M1A1. History of Auto-Ordnance Corp. Florida Drivers License Security Features. And the Thompson Submachine guns. Telephone: 508-795-3919. The first gun produced, bearing neither model or serial number. Dec 13, 2011 Auto Ordance Thompson M1 serial number and markings. The 1928A1's had the 'AO' or 'S' prefix on the serial numbers, but the M1 & M1A1's did. Search Forums. Bomberman Lan Multiplayer Download on this page.

The Thompson Submachine Gun ID Guide, Part V: The Auto-Ordnance, Bridgeport U.S. 1928A1 Thompson Submachine Gun By Frank Iannamico During WWII there was an overwhelming demand for the Thompson Submachine Gun, to supply both U.S. And Allied armies. In 1939, Savage Arms was contracted by Auto-Ordnance to manufacture the weapon. Due to the complex construction of the Thompson, Savage had a difficult time keeping up with the ever-increasing demand. As a result, the Auto-Ordnance Corporation opened their own factory in 1941 to help fill the Ordnance Department’s requirements for the weapon. The 1928A1 Thompson Submachine Guns being produced at Auto-Ordnance’s Bridgeport plant were identical mechanically and in appearance to those being made by Savage in Utica, New York.

The letters AO preceding the weapon’s serial number on the left side of the M1928A1 model’s receiver will easily identify an M1928A1 Thompson that was produced in the Auto-Ordnance’s Bridgeport, Connecticut plant. A similar AO prefix serial number was applied to the rear of the trigger frame. The early manufacture Auto-Ordnance, Bridgeport guns, like their Savage counterparts, were fitted with the finned barrel and the adjustable Lyman rear sight. There were many Savage and other subcontractor manufactured parts used to assemble the guns produced at the Auto-Ordnance plant. The parts that were manufactured in house by Auto-Ordnance were stamped with the letters AO or AOC. As production continued the Auto-Ordnance Thompsons, like the Savage manufactured guns, also began to be fitted with the simple stamped fixed “L” style aperture rear sight.