Thompson Submachine Gun

Origins

Brigadier General John T. Thompson, late of Army Ordnance, set out in 1917 to give the doughboy a one-man "trench broom" for the Western Front. The Armistice arrived before the gun did, and Auto-Ordnance faced the 1920s holding a weapon with no war. The civilian market it found instead was catastrophic for its name: the Model 1921 retailed openly, and motorized bootleggers made the Tommy gun the sound of the Prohibition underworld — the St. Valentine's Day Massacre of 1929 fixed "Chicago typewriter" in the language and helped drive the National Firearms Act of 1934.

Design & Construction

The Thompson fires the fat, subsonic .45 ACP from an open bolt in blowback operation — the 1921/1928 guns dressed the mechanism in a machined-steel receiver of astonishing (and expensive) quality, with a finned barrel, Cutts compensator, Lyman ladder sight, and the famous vertical foregrip. It fed from 20- and 30-round box magazines or the cinematic 50- and 100-round drums. Wartime redesign stripped every refinement: the M1 and M1A1 of 1942 deleted the drums, the compensator, and the fancy sight, moved the charging handle to the side, and halved the cost. At around 4.8 kilograms empty it was heavy for its class, and its cyclic rate of 600 to 700 rounds per minute (higher in the 1928) chewed magazines fast.

Combat Use

Marines carried Thompsons in Nicaragua and China through the interwar years — the US Marine Corps wrote the first real doctrine for it — and Britain bought every gun Auto-Ordnance could ship in 1940, drums and all. In the Second World War it went everywhere Americans fought: squad leaders and scouts in Europe, raiders and jungle patrols in the Pacific, tankers, paratroopers of the 101st Airborne on D-Day, commandos and partisans. Its virtues were the caliber's stopping power and the gun's utter reliability; its vices, weight and a short effective reach. The cruder, cheaper M3 grease gun officially replaced it in 1944, but Thompsons served — and were preferred — to the war's end and beyond into Korea.

Legacy

The Thompson's double image never merged: it is simultaneously the gangster gun of every Prohibition film and the sergeant's weapon in every honest photograph of the American war. Collector-grade Colt-era 1921s and 1928s, registered under the 1934 Act, stand among the most valuable American firearms of any kind, while military M1s anchor WWII small-arms collections. As the weapon that taught the U.S. military what a submachine gun was for, it has no American predecessor and needed no successor with a personality — nothing that replaced it was ever loved the same way.