M1 Thompson “Tommy Gun” Submachine Gun
The Submachine Gun, Cal. .45, M1/M1A1 Thompson was a blowback submachine gun. It was selective for semi- or fully-automatic fire. It fired a .45 cal. cartridge in 20- or 30-round magazines. It’s rate of fire was 700 rpm. The gun was reliable, and continued to operate when similar weapons would have failed due to exposure to battle-field conditions (354,000).
- M1 Thompson was a redesign of the model M1928A1 to simplify production. The M1 had a permanently attached buttstock and a spring-loaded firing pin like the M1928A1. The M1 would not accept the M1928A1 drum type magazine. The M1 had a simple fixed aperture rear sight.
- M1A1 differed from the M1 only in having the firing pin machined into the face of the bolt.
The M1928A1 “Tommy Gun”, a delayed blowback submachine gun. It was issued to armored and reconnaissance units. It was selective for semi- or fully-automatic fire. It fired a .45 cal. cartridge (Colt .45 ACP) in 20- or 30-round magazines, 50-round, or a 100-round drum. It had a leaf with aperture notch battle sight. It’s rate of fire was 600-725 rpm. Original Thompson’s could fire close to 1200 rpm.
The weapon was designed by General John T. Thompson. Thompson prototypes were to be battle tested during World War 1. However, the weapon never made it overseas before the end of the war. Auto-Ordnance, the manufacturer, had to find another market for his innovative submachine gun. The Thompson was marketed to local police departments and to the military. However, there were few buyers due to the cost. It’s original price was $200. The Thompson was next marketed to civilians and the weapon became popular with depression-era gangsters.
The Thompson was first publicly demonstrated in August 1920. Colt firearms made about 15,000 of these weapons under contract when its offer to buy the Auto Ordnance for $1 million was rejected. The Irish Republican Army was the first to use the Thompson in military hit-and-run operations.
Auto Ordnance Corp. sold the weapon during the 1920’s. The U.S. Post Office was the first government organization to purchased these weapons. The U.S. Marines found them essential during the Nicaragua campaign of the late 1920’s and officially adopted them in the early 1930’s. The FBI was issued surplus militarized versions of the Thompson with a special carrying case containing a brass cleaning rod, spare parts kit, 20 and 50 round magazines. The FBI discontinued Thompson use in their field offices in 1974 when it was declared obsolete.
The M1928A1 had a removable buttstock. Most had a horizontal fore grip, but some had a vertical fore grip. The M1928A1 was relatively heavy, and expensive in use of materials, machine time, and machine tools.