- Cartridge: 9 x 19mm Parabellum
- Capacity: 32-round detachable box magazine
- Muzzle Velocity: 1,198 ft./sec.
- Weight: approx. 7.1 lbs.
- Length: 29.9 in.
- Barrel Length: 7.7 in.
- Action: Blowback-operated, open bolt
Sten - Development:
During the early days of World War II, the British Army purchased large numbers of Thompson submachine guns from the United States under Lend-Lease. As American factories were operating at peacetime levels, they were unable to meet the British demand for the weapon. Following their defeat on the Continent and the Dunkirk Evacuation, the British Army found itself short on weapons with which to defend Britain. As sufficient numbers of Thompsons were unavailable, efforts moved forward to design a new submachine gun that could be built simply and cheaply.
This new project was led by Major R. V. Shepherd, OBE of The Royal Arsenal, Woolwich, and Harold John Turpin of the Design Department of the Royal Small Arms Factory, Enfield. Drawing inspiration from the Royal Navy's Lanchester submachine gun and the German MP40, the two men created the STEN. The weapon's name was formed by using Shepherd and Turpin's initials and combining them with "EN" for Enfield. The action for their new submachine gun was a blowback open bolt in which the movement of the bolt loaded and fired the round as well as re-cocked the weapon.
Design & Problems:
Due to the need to quickly manufacture the Sten, construction consisted of a variety of simple stamped parts and minimal welding. Some variants of the Sten could be produced in as few as five hours and contained only 47 parts. An austere weapon, the Sten consisted of a metal barrel with a metal loop or tube for a stock. Ammunition was contained in a 32-round magazine which extended horizontally from the gun. In an effort facilitate use of captured 9 mm German ammunition, the Sten's magazine was a direct copy of one used by the MP40.
This proved problematic as the German design utilized a double column, single feed system that led to frequent jamming. Further contributing to this issue was the long slot along the side of the Sten for the cocking knob which also allowed debris to enter the firing mechanism. Due to the speed of the weapon's design and construction it contained only basic safety features. The lack of these led to the Sten having a high rate of accidental discharge when hit or dropped. Efforts were made in later variants to correct this problem and install additional safeties.
The Sten Mk I entered service in 1941 and possessed a flash hider, refined finish, and wooden foregrip and stock. Approximately 100,000 were produced before factories switched to the simpler Mk II. This type saw the elimination of the flash hider and hand grip, while possessing a removable barrel and shorter barrel sleeve. A rough weapon, over 2 million Sten Mk IIs were built making it the most numerous type. As the threat of invasion eased and production pressure relaxed, the Sten was upgraded and built to a higher quality. While the Mk III saw mechanical upgrades, the Mk V proved to be the definitive wartime model.
Essentially a Mk II built to a higher quality, the Mk V included a wooden pistol grip, foregrip (some models), and stock as well as a bayonet mount. The weapon's sights were also upgraded and its overall manufacture proved more reliable. A variant with an integral suppressor, dubbed the Mk VIS, was also built at the request of the Special Operation Executive. On par with the German MP40 and US M3, the Sten suffered the same problem as its peers in that its use of 9 mm pistol ammunition severely restricted accuracy and limited its effective range to approximately 100 yards.
An Effective Weapon:
Despite its issues, the Sten proved an effective weapon in the field as it dramatically increased the short-range firepower of any infantry unit. Its simplistic design also allowed it to fire without lubrication which reduced maintenance as well as made it ideal for campaigns in desert regions where oil could attract sand. Used extensively by British Commonwealth forces in Northern Africa and Northwest Europe, the Sten became one of the iconic British infantry weapons of the conflict. Both loved and hated by troops in the field, it earned the nicknames "Stench Gun" and "Plumber's Nightmare."
The Sten's basic construction and ease of repair made it ideal for use with Resistance forces in Europe. Thousands of Stens were dropped to Resistance units across occupied Europe. In some nations, such as Norway, Denmark, and Poland, domestic production of Stens began in clandestine workshops. In the final days of World War II, Germany adapted a modified version of the Sten, the MP 3008, for use with its Volkssturm militias. Following the war, the Sten was retained by the British Army until the 1960s when it was fully replaced by the Sterling SMG.
Produced in large numbers, the Sten saw use around the world after World War II. The type was fielded by both sides of the 1948 Arab-Israeli War. Due to its simple construction, it was one of the few weapons that could be produced domestically by Israel at that time. The Sten was also fielded by both the Nationalists and Communists during the Chinese Civil War. One of the last large-scale combat uses of the Sten occurred during the 1971 Indo-Pakistani War. On a more notorious note, a Sten was used in the assassination of Indian Prime Minister Indira Gandhi in 1984.