Sten Mk II(S)
Royal Small Arms Factory Enfield · Submachine Gun · Discontinued · 1943
Also known as: Sten Mark IIS, Sten Mk IIS, Sten Mk 2(S), Carbine, Machine, Sten, 9mm Mk 2(S), Silenced Sten
Overview
The Sten Mk II(S) is an integrally suppressed British submachine gun developed in 1943, a clandestine-operations adaptation of the standard Sten Mk II. Its 'S' designation stands for 'Special Purpose'. A drastically shortened, ported barrel vents propellant gas into a roughly 12-inch suppressor jacket containing an expansion chamber and 18 baffles, dropping muzzle velocity from around 365 m/s to about 300 m/s to keep the 9x19mm round subsonic. The bolt was lightened by roughly 15 percent and the recoil spring shortened to ensure reliable cycling with the reduced gas energy. Though capable of automatic fire, the gun was normally fired single shot or in short bursts to avoid overheating and damaging the baffles. Built for the Special Operations Executive, it equipped agents and resistance forces in occupied Europe.
Specifications
| Weight (empty) | 3900 g (137.6 oz) |
| Weight (loaded) | 4500 g (158.7 oz) |
| Overall Length | 902 mm (35.51") |
| Barrel Length | 95 mm (3.74") |
| Height | 195 mm (7.68") |
| Width | 180 mm (7.09") |
| Action Type | Blowback |
| Firing Mechanism | Open Bolt |
| Trigger Type | Single Action |
| Magazine Capacity | 32 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 300 m/s (984 fps) |
| Muzzle Energy | 335 J (247 ft·lbf) |
| Effective Range | 70 m (77 yd) |
| Maximum Range | 150 m (164 yd) |
| Rate of Fire | 450 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 250 mm (9.84") |
| Number of Grooves | 6 |
| Frame Material | Steel |
| Barrel Material | Steel |
| Stock Material | Steel |
| Finish | Phosphate |
Calibers
- 9x19mm Parabellum · primary · 9mm NATO — also known as 9mm Luger, 9mm NATO, 9x19mm
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety Slot, Bolt Locking Notch
- Features: Integral Suppressor, Ported Barrel, Shortened Barrel, Lightened Bolt, Side Mounted Magazine, Skeleton Stock
Base model
Service history
Operators
- Special Operations Executive · adopted 1943
- British Army · adopted 1944 · as Carbine, Machine, Sten, 9mm Mk 2(S)
- Office of Strategic Services · adopted 1943
Conflicts
- World War II (1939-1945)
Production
Estimated total produced: 5,776 · Production years: 1943-1945
Approximately 5,776 Mk II(S) units produced, with volume manufacture beginning February 1944; first operationally used by SOE in 1943.
Origin
Country of origin: United Kingdom
Designer: R. V. Shepherd, H. J. Turpin
Discontinued: 1945
Notes
The 'S' stands for 'Special Purpose', not 'Silenced'. The shortened barrel (about 95 mm) carries six vent holes ahead of the chamber to bleed velocity. Owing to overheating, the suppressor required a leather hand-guard and the gun was fired in short bursts or single shots. Succeeded conceptually by the Sten Mk VI, the integrally suppressed Mk V.
Background
Built for the Special Operations Executive's covert war in occupied Europe, the suppressed Sten let agents and partisans eliminate sentries quietly. Its development is variously credited to Major Hugh Reeves (later of Welrod fame) and to the Polish engineer Lt. Kulikowski working at Enfield.