The STEN name was derived from the names of the designers (R. V. Shepard and H.J. Turpin) and from the factory where they worked (the ENfield arsenal). The weapon was a simple design, developed in mid 1941 to fill an urgent need after the fall of France. In Britain weapons were in very short supply and with a German invasion feared, an easy to manufacture sub-machine gun was seen as the quickest way of re-equiping the army for home defense.
The Sten was a blowback operated weapon that fired from an open bolt. The tubular receiver and the barrel shroud were made from rolled steel. The gun was fed from a left side mounted magazine. The stock was of the skeleton type, made from steel. The sights were fixed, adjusted for 100 yards distance, a peep hole rear aperture and a blade front. The MkI featured spoon-like muzzle jump compensator. Some guns had a small forward folding grip.
The magazines were often loaded with 30 rounds instead of the full capacity of 32, to reduce strain on feed springs. Some were manufactured with integral silencers for undercover operations and were designated as the Mk.II(S). Rate of fire was around 500 rounds per minute. Normal operation for weapons of this type is for the user to fire 4-8 round bursts.
The Sten's poor reputation was partially due to its rushed introduction into service combined with the inexperience of the new recruits that were being hastily trained to bring the army up to strength in expectation of the German invasion. Problems with the MkI soon became obvious and these were rectified in subsequent models. Total production was more than 4 million when manufacturing ceased in late 1944.
In its intended role the Sten was actually quite a capable weapon. Originally envisaged to be used in relatively "clean" conditions, ie, urban or open areas as anticipated in England or Europe, when moved to the harsher "dirty" environment of Pacific jungle warfare its shortcomings soon became apparent. The side mounted magazine made it awkward to use in dense jungle while the weapon's intolerance to mud, water and foliage - particularly the tendency for the side mounted exit port to allow leaves and twigs to jam the bolt action - added to its original poor reputation. It was partially because of these problems that the Australian Owen gun was designed with a vertical magazine and a bottom exit port making it less prone to fouling.
A version was manufactured in Australia as a stop gap measure until the introduction of the Owen gun. Commonly known as the Aust-Sten (or Austen) it incorporated many of the modifications learned from the Mk1.
For some reason the Services Reconnaissance Department retained the Sten as one of its standard weapons - possibly due to the relationship between the SRD and the British Strategic Operations Executive with which it had its origins.
Many of the problems with the Sten were eliminated by rebuilds carried out by Z Special armourers, however its major shortcomings - the side mounted magazine and ejection port, continued to plague users.
All members of the Muschu reconnaissance team carried Sten guns. Read the narrative of The Guns of Muschu to see how the weapon was put to good use.