The Sten submachine gun has a very peculiar history and while many think that it has been deemed obsolete, as little as ten years ago was still being used in combat in Chiapas, Mexico.
The Sten was a horrible gun, a poor quality shooting thing that was designed and saw mass production only because the British were desperate to counter the effects of the modern and well-built submachine guns with which the Germans wiped the allied forces in 1939 and 1940. It was an awful gun that could have been considered obsolete the same day the first prototype shot the first bullet and its story was one of hate at first sight with the British soldiers.
It received nicknames lie ´The plumber's delight´ and ´The stench gun,´ yet, millions of Stens were produced in many different versions and the weapon itself was copied at least in Argentina and Germany, also for mass production, and also copied and hand crafted in Afghanistan. Indeed it served a purpose and before the appearance of the Kalashnikov was the gun produced in the biggest numbers in history: at least six million Stens left the production lines, so to speak.
And we cannot speak properly about production methods for the Sten because its main peculiarity was that it was designed to be produced in almost any sort of factory or repair shop using very simple tools and widely available materials: Even common tubes and steel rods from construction and demolition sites were used - hence, the references to the plumbing vocation - and that made the weapon exceedingly cheap and easy to manufacture. In this way, Sten production could be outsourced from factories that could be bombed easily and into small shops and even homes that would present an impossible target for the German Luftwaffe.
Most Stens shot the now standard 9 mm. Parabellum round, which was chosen by the British after they captured a large Italian arsenal in Northern Africa; some others were chambered for the U.S. .45 round, but they did not see wide use. The fact that NATO uses now the 9 mm. Para in pistols and submachine guns is owed to the Sten gun that was promptly replaced by the Sterling gun, a conceptually similar design appeared in 1945, but of much higher quality. Both weapons had a pretty standard magazine that was placed sideways, to the left side of the gun instead of the almost-standard placement in today's automatic, semiautomatic and selective fire weapons, which is downwards.
The characteristics of this design made the Sten easier to use while lying on the ground: Long magazines would not disturb the shooter or make him adopt a vulnerable posture that would increase the target area that they presented to the enemy. So the weapon wasn't without any merit. The design is a clear example of what happens as countries find themselves at war, trying to defend themselves with scarce resources, confronted by enemies with advanced technologies and greater firepower, but with enough wit to respond appropriately.
In terms of weapon's design, it would be interesting to reconsider the blueprints of the Sten perhaps with some upgrading in areas like alloys and safety devices; as its designers stated more than once, the Stens also shot bullets like the German MPs, but were a lot cheaper. So it wouldn't be a bad idea for officers dealing with logistics and politicians considering the building up of armed forces to take into account the apparently obsolete and certainly loathed Stens.