- Weight: 7.1 lbs
- Length: 29.9 in
- Barrel Length: 7.7 in
- Cartridge: 9x19mm Parabellum
- Action: Blowback operated, open bolt
- Rate of Fire: ~500 rounds/min
- Muzzle Velocity: 1,198 ft/s
- Effective Range: 220 yards
- Feed System: 32 round detachable box magazine
- Sights: Fixed peep rear, post front
The Sten was used by the British and Commonwealth forces during World War II, the Korean War, and numerous other campaigns. Like many of their weapons, the Yakuza acquired these guns via the black market. The weapon is widely used as its parts can be easily manufactured.
In the first months of WWII the Thompson submachine gun was the most common submachinegun in the UK. But as imports and supplies weakened; the British created the Sten as a cheaper yet sill effective automatic weapon they could mass produce themselves. The Nazi MP 40 was a primary inspiration for the Sten.
The Sten Mk II used less parts than the Mk I: costing only $160 (in 2017 USD) per gun. Only the barrel and the bolt were 'machine parts'. Much of the gun was made of the cheapest steel stamping: including springs identical to those foundin spring beds.
4 million Stens were made in WWII: half being the Mk II.
In WWII: the Allies donated the Sten to anti-fascist parties within the Nazi Empire; as the gun was easy to maintain and small enough to hide. The light and small size made it easy to conceal and use to ambush or assassinate. Some rebels managed to build the gun on their own since the design was so simple. The 9x19mm ammo was one of the most common pistol cartridges in the world at that time; although the Sten could be built or modified to hold different types of ammo.
However the Mk II's simplicity gave it severe flaws. Slamfires were common and could potentially unload the entire clip. Misfires and jams could be caused by the slightest impacts, mud, dust, water or dirt. The UK military trashed thousands of Mk IIs for being too unreliable for combat. "Stench Gun" and "Plumber's Nightmare" were common nicknames for the faulty gun.