The STEN need was determined by the British Government during the summer of 1940 - having lost a lot of men and material on the retreat and beaches of Dunkirk. The German forces at that time were observed to have more Full Automatic Small arms dispersed amongst every level of unit encountered. The US was selling as many of the Thomsons as could be agreed and produced - but theses were expensive - even after cost cutting and process simplification exercise waves - their supply was also threatened by the German Submarine Wolf Packs. With so many aspects of the forlorn struggle to deal with a Full Automatic Small Arms solution task was assigned to Enfield Lock. The solution was quickly found to be a tube-gun with simple monolithic machined bolt and as many fabricated parts as possible to spare machining resources. Major Shepard and Mr Turpin are credited with the design (which was 1/3 of the cost of a Thomson) - each taking the initial of their surname and the EN of Enfield to derive the platforms name - S.T.EN. Typically the designs allowed the use of captured German MP40 magazines and used the same 9mm luger ammunition, the buttstock was a push button removable device and with a closing plate or pistol grip would be no longer than 20 inches to conceal. Silenced versions were developed and different format bayonets were designed as well as a lot of other small production and local improvisation. There would be 5 marks of the device developed over the remaining war years - some specialized for light production and others reinforced for elite troops - these stayed in service with British forces until the 1950's where the Stirling would take up the task. STENs are still encountered in combat around the world in the hands of rebels, resistance and insurgent forces.
Here we see the left perspective of the Mk5 Sten - developed for Airbourne troops - these platoons would have A STEN per NCO (2) and either a BREN, PIAT or 2" Mortar as well as a designated marksman (sniper) with No4T. This device is shown with the magazine housing rotated down to cover the feed and ejection ports to keep foliage, dirt and debris clear of the works. It has an indent on its front edge that registers in a hole in the receiver tube when turned to the "active" position. There are interchangable / borrowed components from the Mk2 design - such as the barrel collar and shroud, the bolt body, extractor and content components of the trigger group. Beyond that, it may look similar but components and functions are different to the Mk2. This being a premium specialized model for paratroopers. The barrel had the No4 rifle bayonet fitting and front sight block tennons machined on - allowing the No4 sight system and bayonet to be used (mk2 spike during WW2 - No7 convertible bayonet post war). The wooden butt stock was shaped similar to the No 4 rifle example, but had no through hole - instead the front edges were tapered to take a plat that latched onto the receiver closing plate. Most were finished with a No4 rifle brass butt plate and the cleaning kit holw was present. Some economy bitts go exist where the butt plate is a simplified flat steel device. The mounting plate from the No4 rifle butt swivel was used - on top of the butt rather than under - with a simple C loop to attach the STEN format sling. The wood furniture is finished with a a contoured pistol grip that was unique to the Mk5 - this shortened the firing group and pushed it forward on the receiver to accomodate the tang and screw hole. This example has a clip on wooden handle onto the barrel shroud - this can slip around to move from vertical to horizontal or any angle in between.
This example is a legally built transferable Semi-Automatic device based on a kit designed, produced and BATF certified by Indianapolis Ordinance (IO). It was built and unique serialed by a manufacturer class FFL and has a choice of barrels - this dummy / solid short barrel for re-enactments, a blank fire barrel for tactical events and a live fire long barrel in 9mm to have it as a Semi-Auto rifle. Within the IO design - the receiver tube is a smaller diameter and cannot take a FA bolt (which is also fire on close / fixed striker), the new / necessary SA bolt is captive hammer energizing with an AR15 firing pin and return spring incorporated. This then necessitates two springs - one for the bolt close and one to energize the hammer. Both springs are held on a guide rod and separated at the back end by a spacer which can welded to add stability - this assembly fitting inside the standard action cover. The extra spring pressure does not allow the original safety notch to be reached easily, so the kit and instructions allow for the selector to become a safety catch.
Here we see this devices right side perspectives. The bolt handle is a unique profile for the Mk5 version - all STEN bolts insert at into a deep hole in the bolt when the bolt is drawn back to the enlarged diameter at the far rear of the bolt groove. This is done with the end cap off and all spring pressure released.
Other views and details of the device.
In future article updates I will add views of the various buttstock examples and designs, as well as replica accessories like action covers, paratrooper magazine bandoliers and replica non-functioning silencers.
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