Sten

Sten submachine gun
Sten submachine gun
	A Sten MK II
Type	Submachine gun
Place of origin	United Kingdom
Service history
In service	1941–1960s (United Kingdom); 1941–present (other countries);
Used by	See Users
Wars	World War II; Second Sino-Japanese War; Chinese Civil War; Indonesian National Revolution; First Indochina War; Indo-Pakistan Wars; 1948 Arab–Israeli War; Malayan Emergency; Korean War; Mau Mau Uprising; Algerian War; Suez Crisis; 1958 Lebanon crisis; Cuban Revolution; Annexation of Goa; Portuguese Colonial War; Sino-Indian War; Vietnam War; Indonesia–Malaysia confrontation; Laotian Civil War; Greek Civil War; Bangladesh Liberation War; Lebanese Civil War; Angolan Civil War; Rhodesian Bush War; Turkish invasion of Cyprus; IRA Border Campaign; The Troubles; Punjab insurgency; Maluku sectarian conflict; Iraq War; Syrian Civil War;
Production history
Designer	Major Reginald V. Shepherd; Harold J. Turpin;
Designed	1940
Manufacturer	Royal Small Arms Factory Enfield; BSA; ROF Fazakerley; ROF Maltby; ROF Theale; Berkshire; Lines Brothers Ltd; Long Branch Arsenal, Canada; Various underground resistance group factories;
Unit cost	£2/6s in 1942 (equivalent to £135 in 2023)
Produced	1941–1945 (version dependent)
No. built	3.7–4.6 million (all variants, depending on source)
Variants	Mk. I, II, IIS, III, IV, V, VI
Specifications
Mass	3.2 kg (7.1 lb) (Mk. II)
Length	762 mm (30.0 in)
Barrel length	196 mm (7.7 in)
Cartridge	9×19mm Parabellum
Action	Blowback-operated, open bolt
Rate of fire	version dependent; c. 500–600 round/min
Muzzle velocity	365 m/s (1,198 ft/s) 305 m/s (1,001 ft/s) (suppressed models)
Effective firing range	60 m (66 yd)
Feed system	32-round detachable box magazine
Sights	fixed peep rear, post front

The STEN (or Sten gun) is a British submachine gun chambered in 9×19mm which was used extensively by British and Commonwealth forces throughout World War II and during the Korean War. The Sten paired a simple design with a low production cost, facilitating mass production to meet the demand for submachine guns.

As well as equipping regular units, the Sten was distributed to resistance groups within occupied Europe. Its simple design made it an effective insurgency weapon for resistance groups.

The Sten is a select fire, blowback-operated weapon with a side-mounted magazine. Sten is an acronym, derived from the names of the weapon's chief designers: Major Reginald V. Shepherd and Harold J. Turpin, and "En" for the Enfield factory. Around four million Stens in various versions were made in the 1940s, making it the second most produced submachine gun of the Second World War, after the Soviet PPSh-41. The Sten served as the basis for the Sterling submachine gun, which replaced the Sten in British service from the 1950s.