Sten

From Wikipedia, the free encyclopedia

Carbine, Machine, Sten
Sten Mk. IIS
Type	Submachine gun
Place of origin	United Kingdom
Service history
In service	1941-1960s
Used by	United Kingdom, Commonwealth, Norway, Free French, Partisans
Wars	World War II, Korean War, Suez Crisis
Production history
Designer	Major Reginald V. Shepherd Harold J. Turpin
Designed	1940
Manufacturer	Royal Small Arms Factory, Enfield
Produced	1941-Version dependent
Number built	3.7-4.6 million (all variants, depending on source)
Variants	Mk. I, II, IIS, III, IV, V, VIS
Specifications
Weight	(Mk. II) 3.18 kg
Length	(Mk. II) 760 mm
Barrel length	196 mm

Cartridge	9 mm Luger Parabellum
Calibre	9 mm
Action	Blowback-operated, Open bolt
Rate of fire	version dependent ~500 round/min
Muzzle velocity	1200 ft/s (365 m/s) non-suppressed versions
Effective range	50 yards (46 m)
Feed system	32 round detachable box magazine

This article is about the submachine gun. For the name "Sten", see Sten (name)

The Sten (or Sten gun) was a family of British, 9 mm submachine guns used extensively by the British Empire and Commonwealth forces throughout World War II and the Korean War. They were notable for their simple design and comparatively low cost of production. The name STEN is an acronym, deriving from the names of the weapon's chief designers, Major Reginald Shepherd and Harold Turpin, and ENfield, the location of the Royal Small Arms Factory (RSAF) at Enfield Lock in London. Over 4 million Stens in various versions were made in the 1940s.

The official designation Carbine, Machine, Sten should not be confused with the common understanding of carbine; the Sten was a typical, almost stereotypical submachine gun while the term carbine is used to refer to short, light rifles of full caliber.

1 History
2 Design
3 Variants
4 Service
5 Trivia
6 See also
7 External links

[edit] History

The Sten was designed at a time when Britain was engaged in the Battle of Britain and other fighting throughout the world, and facing the danger of being invaded by the Nazis. Weapons had been lost during the evacuation from Dunkirk and the army was being expanded. Prior to 1941 (and even later) the British were purchasing all the Thompson submachine guns they could from America, but this did not begin to meet demand. The American entry into the war at the end of 1941 placed an even bigger demand on the facilities making Thompsons. In order to rapidly equip a sufficient fighting force to counter the Axis threat, the Royal Small Arms Factory, Enfield, was commissioned to produce a significantly cheaper alternative.

The credited designers were Major R. V. Shepherd, OBE, Inspector of Armaments in the Ministry of Supply Design Department at The Royal Arsenal, Woolwich, (later Assistant Chief Superintendent at the Armaments Design Department) and Mr. Harold John Turpin, Senior Draughtsman of the Design Department of the Royal Small Arms Factory (RSAF) Enfield. Shepherd had been recalled to service after having retired and spending some time at BSA.

The Sten required a minimum amount of machining and manufacturing effort by using simple pressed metal components and minor welding. Much of the production could be performed by small workshops and the guns assembled at the Enfield site. Over the period of manufacture the Sten was further simplified, the most basic model, the Mark III, could be produced from five man-hours work. Some of the cheapest versions were made from only 47 different parts. It was distinctive for its bare appearance (just a pipe with a metal loop for a stock), and its horizontal magazine. The Mark I was a more finely finished weapon with a wooden foregrip and handle, some later versions were not quite as spartan.

The Sten was slowly withdrawn from British service in the 1960s; replaced by the Sterling SMG. The other Commonwealth nations made or adopted their own replacements.

[edit] Design

The Sten gun was chambered for the 9 x 19 mm Parabellum pistol cartridge, which was useful in that captured German ammunition supplies could be used. The Sten was small and could be stripped down into a set of easily concealed components and was therefore particularly suited to partisan operations on the continent. Guerrilla fighters in Europe became adept at repairing, modifying and eventually scratch-building clones of the Sten (over 2000 Stens and about 500 of similar Błyskawica SMGs were manufactured in occupied Poland).

The Sten was often disparaged by soldiers for its inaccuracy due to basic sights, which were often not even zeroed for an impact point. Stoppages also occurred due to the poorly-designed magazine (a direct copy of the German Erma MP38/MP40 magazine). The magazine had two columns of tapered 9 mm cartridges arranged side-by-side in a zig-zag manner. To allow the magazine box to be straight, the front of the magazine was tapered to complement the taper of the cartridges. While other staggered magazines fed from both the left and right positions, the Sten magazine required the cartridges to gradually merge at the top of the magazine to form a single column. Any dirt or foreign matter in this taper area frequently caused feeding malfunctions. Additionally, the walls of this lip had to endure the full stresses of the rounds being pushed in. This often resulted in deformation of the lips, resulting in misfeeding. Modern 9 mm magazines like that of the Sterling SMG are curved and feed both sides to avoid this problem.

The slot on the side of the body where the cocking knob ran was a target of criticism, as the long opening allowed plenty of opportunity for foreign objects to enter.

Additionally, the MK II and MK III Stens were highly prone to accidental discharge if dropped or knocked over, and a number of accidental shootings of friendly troops occurred throughout the war. The design received various design changes and improvements over the course of the war, and the Mark V version, introduced in 1944, remained an issue weapon in the UK until well into the 1960s. The Sten was replaced in the UK with the Sterling SMG which came into service in quantity in 1953, and in Canada by the similar C1 Submachinegun in 1958.

Such was the ease of manufacture that the Germans also produced a version of the Sten, the MP 3008, late in the war. A move born of desperation due to shortages of labor and materals, it was ironic in view of the fact that the weapon which had inspired the Sten was the German MP38.

[edit] Variants

Sten guns were produced in several basic marks, (though the MKI saw limited service, and the MKIV was never issued) and nearly half of the total produced were of the Mark II. Approximately 4.5 million Stens were produced during the war.

[edit] Mark I

This rare weapon had a conical flash hider and finest finish. It had a wooden foregrip and forward handle (sometimes this was made of steel), as well for a section of the stock. The stock was a small tube outline, rather like the Mark II Canadian. One unique feature was that the front pistol grip could be rotated forward to make the firearm easier to stow. The barrel sleeve extended all the way to the end, where it had conical flash hider. Along the top of the tube surrounding the barrel was a line of small holes and its sights were configured somewhat differently. About 100,000 were made before production switched to the Mark II. Sten Mk I's in German possession were designated MP.748(e).

Mark I:

Overall Length: 35.3 inches (896 mm)
Barrel Length: 7.8 inches (198 mm)
Weight: 7.2 pounds (3.8 kg)

Female worker posing with a Sten in a Canadian factory, 1942

[edit] Mark I*

This was the first simplification of the Mk I. The foregrip, the wooden furniture and the flash hider were deleted for production expediency.

[edit] Mark II

The Mark II was the most prolific, at 2 million units. It was a much rougher weapon than the Mk I. The flash eliminator and hand guard (grip) of the Mk I were eliminated.

Other changes included a removable barrel which projects 3 inches beyond the barrel sleeve and the magazine housing rotates to form cover for ejection opening.

Winston Churchill tests a Sten Gun, 1941. Note the man standing in the background, Walter Thompson, Churchill's bodyguard.

The barrel sleeve was shorter and rather than have small holes on the top, it had three on the side on the lower part of the shroud. Sten Mk II's in German possession were designated MP.749(e).

There were some MkIIs that were fitted with a wooden stock and there was also a silenced version (see below).

Regular Mark II:

Overall Length: 30 inches (762 mm)
Barrel Length: 7.8 inches (197 mm)
Weight: 6.7 pounds (3.0 kg)

[edit] Mark II (Canadian)

During World War II a version of the Sten gun was produced at the Long Branch Arsenal in Long Branch, Ontario now part of Toronto, Ontario. This was very similar to the regular Mark II, but was of a little better quality and it had a different stock. It was produced in Canada at the Long Branch factory. It was first used in combat in the Dieppe Raid in 1942.

[edit] Mark III

This simple design was the next most commonly produced after the Mark II. It was a simplification of the MkI. It was made both in Canada and the UK with the latter's Lines Brothers the biggest manufacturers. The biggest visual difference from the Mark II, was that the barrel shroud extended farther up the barrel. Its main differences technically were that the barrel was fixed and the body was welded shut along the centre of the top. Sten Mk III's in German possession were designated MP.750(e).

[edit] Mark IV

The Mark IV was a smaller version which did not progress beyond the prototype stage. It was near pistol-sized and it had a different configuration with a conical flash hider, a rear pistol grip, a very light stock and a much shorter barrel.

[edit] Mark V

British paratroopers in Oosterbeek armed with Sten Mk V

This was commonly issued to paratroopers and was used in Normandy and at Arnhem. Changes included wooden pistol grips including a fore grip, a stock, and a bayonet mount. The forward grip would often snap off. The Sten bandolier which paratroopers were issued with held 7 full magazines.

[edit] Mark VI

Overall Length: 35.8 inches (908 mm)
Barrel Length: 7.8 inches (198 mm)
Weight: 9.8 pounds (4.45 kg)

[edit] Suppressed models

Mark IIS and Mark VIS models (sometimes recorded as 6(s)) were produced which incorporated an integral supressor. This would heat up rapidly when fired and a canvas cover was laced around for some protection. The Mark 6 had a lower muzzle velocity than the others; 305 m/s (1000 ft/s) and was also the heaviest regular version due to the added weight of the specially designed silencer, as well as using a wooden pistol grip and wooden stock. Sten Mk IIS's in German possession were designated MP.751(e).

The weapons were usually used on semi-automatic fire, rather than full-automatic because of the suppressor's rapid heat build up in full-automatic firing. It was also claimed that vibration during full-auto fire would cause the bullets to clip the suppressor's internal baffles, damaging it.

The suppressed models were produced at the request of the Special Operations Executive (SOE) for use by their teams in occupied Europe. Starting with the Mk. IIS in 1943.

[edit] Foreign built copies and derivatives

Norwegian Sten

In German-occupied Norway the resistance, under leadership of Bror With, created a large number of Sten guns from scratch, mainly to arm members of the underground army Milorg. The same was done to some extent in Denmark.

Polish Sten

The Polish resistance was provided with numerous Stens of various models by the SOE and the Cichociemni. Between 1942 and 1944, approximately 11,000 Sten Mk IIs were delivered to the Armia Krajowa. Due to the simplicity of design, local production of Polish variants of Sten was started in at least 23 underground workshops in Poland. Some of them produced copies of Mark IIs, while others produced the so-called Polski Sten. The Polski Sten made in Warsaw under command of Ryszard Białostocki were built from a number of legal elements made in official factories or acquired through other means. The main body of the machine pistol was made from hydraulic cylinders produced for hospital equipment. All the pistols were marked in English to disguise their origin and the production facilities. A modernized version of Sten was produced in Poland under the name Błyskawica.

Gerät Potsdam In late 1944, the Mauser works started a series of copies of British Mk II Sten for diversion and sabotage purposes. The series was nick-named the Gerät Potsdam and amounted to roughly 28,000 pieces made.

MP 3008

In 1945, Germany was seeking a cheap machine pistol for the Volkssturm. For that purpose a modified Sten was designed by Mauser and named the MP 3008. The main difference was the magazine attached below the weapon. Altogether, roughly 10,000 pieces were produced until the end of World War II.

[edit] Service

The Sten, especially the Mark II, tended to attract affection and loathing in equal measure and its questionable reliability and durability made it unpopular with many front-line troops. It gained nicknames such as "Plumber's Nightmare", "Plumber's Abortion", "Stench Gun" or "Woolworth's Gun". Its main benefit was availability in the numbers desired by troops, resistance groups and support services.

Stens were airdropped to resistance fighters and partisans throughout occupied Europe. Due to their slim profile and ease of dismantlement, they were good for concealment and guerrilla warfare.

American officer and French partisan, 1944.

However, a famous engagement involving a Sten - the assassination of Reinhard Heydrich - was almost thwarted when the Sten jammed. This problem also occurred with the German MP40 magazine, which was copied by the designers for the Sten.

Canadian infantry battalions in North-West Europe held spare Sten guns for special missions and the Canadian Army reported a surplus of the weapons in 1944. The Sten was not used in Italy due to constraints on the shipping of ammunition; .45 calibre ACP was already being used in theatre by the US Army and a requirement for 9mm would have been in competition with limited shipping space.

The Sten saw use even after the economic crunch of the Second World War, replacing the Royal Navy's Lanchester submachine guns into the 1960s and was used in the Korean War including specialist versions for British commandos. It was slowly withdrawn in the 1960s and replaced by the Sterling SMG in British Army service, while Canada adopted a similar weapon, the C1 SMG to replace the Sten.

In the 1950s "L numbering" came into use in the British Army for weapons - Stens were then known as L50 (Mk II), L51 (Mk III) and L52 (Mk V).

[edit] Trivia

Holding and firing the Sten using the magazine as a grip, a method made popular by various movies and video games (ex: Call of Duty), is incorrect. The weapon should be fired holding the barrel shroud. Holding the magazine and firing can cause the rounds to feed incorrectly, jamming the weapon.
Due to poor quality of the spring in the magazine, soldiers would commonly load 28 to 30 rounds instead of the full 32. This was done in an attempt to maintain the strength of the spring and reduce jamming.
The Sten had a tendency to continue firing (on automatic mode) after a finger was taken off the trigger, this is one of the reasons people tried holding the weapon by the magazine, had it started to fire after the trigger was let go, the magazine could be taken out stopping the fire and saving ammunition.
The Sten was used extensively by Jewish partisans during the Israeli War of Independence. These Stens, and their ammunition, were often produced from scratch in secret factories on Kibbutzim. Many Israeli-made Stens were stamped USA for Unser Sticke Arbeit, Yiddish for "our piece of work", but intended to mislead the British into thinking the United States was supplying the Jewish rebels with munitions.