Type	Submachine gun
Place of origin	United States

Service history

In service	1938–1971 (officially, U.S. military) 1921–present (other countries)

Wars	Chaco War Banana War Irish Civil War World War II Indonesian National Revolution Chinese Civil War First Indochina War Greek Civil War 1948 Arab–Israeli War Korean War Algerian War Vietnam War The Troubles Yugoslav Wars Iraq War and numerous others

Production history

Designer	John T. Thompson
Designed	1917–1920
Manufacturer	Auto-Ordnance Company(originally) The Birmingham Small Arms Company Limited Colt Savage Arms RPB Industries
Produced	1921–1945
No. built	Approximately 1.75 million of all variants, including:562,511 M1928A1 285,480 M1 539,143 M1A1

Specifications

Mass	10.8 lb (4.9 kg) empty (Thompson M1928A1) 10 lb (4.5 kg) empty (Thompson M1A1)
Length	33.7 in (860 mm) (M1928A1 with compensator) 31.9 in (810 mm) (M1/M1A1)
Barrel length	10.52 in (267 mm) 12 in (300 mm) (with Cutts compensator)
Cartridge	.45 ACP (11.43×23mm)
Action	Blowback, Blish Lock
Rate of fire	approx. 830 rpm (M1928), approx. 625 rpm (M1A1), 1500 rpm (M1919)
Muzzle velocity	935 ft/s (285 m/s)
Effective firing range	164 yds (150 m)
Feed system	20-round stick/box magazine 0.4 lb (0.2 kg) loaded 30-round stick/box magazine 0.5 lb (0.2 kg) loaded 50-round drum magazine 2.6 lb (1.2 kg) loaded 100-round drum magazine (M1 and M1A1 models do not accept drum magazines)