While the ongoing Coronavirus pandemic has prevented some archival research I had planned which would have informed much of the STEN series, our good friend Richard at the Vickers Machine Gun Collection and Research Association, has come to our aid and we’re able to cover some of the loading accessories developed for the Sten’s magazines.
As we know the Sten uses a 32-round double stack, single feed magazine which can trace its origins back through the Lanchester Machine Carbine to the Haenel MP28,II’s magazine designed by Hugo Schmeisser [patented in 1931].
The nature of the single feed makes the magazine difficult to load by hand with the last few rounds very hard to insert. So a series of four marks of ‘magazine fillers’ were developed. These are described in the British Army’s official List of Changes in February 1943.
The MkI is described as consisting of “a lever mounted on a short case which conforms to the shape of the magazine. It is hand operated, the loading lever being given a rocking motion during filling. The MKI slipped over the top of a magazine with a rivetted spring tab which indexed into a notch in the front of the Sten mag.
The MkII is very similar but simplified by having the spring catch mounted on the rear instead of the side and engaged a “small rectangular slot on the magazine”. The rear of the spring is turned up slightly to allow the user to remove its from the magazine.
The MkIII, which is possibly the rarest of the fillers, is described as:
“hand operated but of different design from the MkI and MkII. It consists essentially of a spring loaded vertical plunger which is attached externally to a case, the latter to assemble on the magazine. There is no retaining catch. It comprises the following parts:
Case. Is a rectangular shaped steel pressing with a tube of rectangular section welded thereto. The latter, which houses the plunger and spring, has a hole trilled at the lower end to accommodate a pin which restricts the amount of movement of the plunger and acts as a stop for the compressing spring.
Plunger, loading. Is made of two laminated steel strips welded together the top part of which is set to form a handle. The body of the plunger is slotted to accommodate the compression spring. The top part is splayed to form a suitable contact with the cartridge.”
List of Changes, Feb. 1943
The other more common filler is the MkIV. Which is a much simpler design with a loading lever mounted on top of a clip which is attached to the rear of the magazine body and retained by a spring similar to that of the MkII.
Rich has very kindly demonstrated the use of the two most common fillers – the MkII and the simpler MkIV. It takes Rich just under 2 minutes to load that magazine, but he was doing his best to show various angles and unlike a British soldier during the war he hasn’t regularly loaded magazines with one of these fillers either. Despite that the clip gives a good idea of how fast you could load a mag once you’re in the groove.
With the MkIV filler Rich was able to load the mag in about 1 minute 15 seconds, the stability of resting the base of the mag on the table helped with the MkIV’s simpler design.
Also, as a follow on to our previous episode looking at the Sterling Submachine Gun’s magazine Rich has also demonstrated the loading of a Sterling mag to its 34 round capacity. No magazine filler needed with George Patchett’s double-stack, double feed magazine.
The Sten is one of Britain’s iconic Second World War Small arms. Two men are principally responsible for its development Colonel Reginal Vernon Shepherd and Mr. Harold John Turpin a pair of small arms and engineering experts with considerable experience.
Turpin was born in Kent in 1893, served his apprenticeship as a draughtsman in Erith and in 1922, he joined the drawing office at the Royal Small Arms Factory Enfield – Britain’s principal state small arms centre.
Reginald Shepherd was born in 1892, received an Bachelor of Science Degree from Leeds University in 1912. In October 1914, he joined the West Yorkshire Regiment as a second lieutenant, serving in Gallipoli and Egypt. After the war, with his engineering background, he assigned as 2nd Assistant Superintendent at the Design Department at RSAF Enfield in December 1922, and promoted to captain.
The two men found themselves joining Enfield at around the same time. In November 1933, Shepherd, now a major, was appointed Inspector of Small-Arms (Class 2) at Enfield and assisted in getting the Bren light machine gun into service. He remained at Enfield until 1936, when he retired from the army and spent a short spell at BSA before being recalled. In late 1939, Major Shepherd returned to active service and once again took up the position of Inspector of Armaments, this time at the Ministry of Supply Design Department at Woolwich Arsenal.
By the outbreak of the Second World War Turpin had become the senior draughtsman at Enfield and when the development of the Lanchester Machine Carbine began he was paired with Major Shepherd to draw up technical drawings for the gun’s production.
The two men decided that a simpler, cheaper submachine gun could be produced and in December 1940 set about designing it, with Turpin in the lead. During the Winter of 1940-41 the first prototypes were built. Development of the first Sten – the T40, was completed on 8th January 1941, taking just 36 days.
14 pilot models were ordered but only two were completed by engineers at the Philco Radio Works in Middlesex: T-40/1 and T-40/2. The gun was initially designated the ‘T-40’ or Turpin, 1940. By the end of January 1941, it had become known as the ‘ST Machine Carbine’. The ‘Carbine, Machine, STEN, MkI’ was approved for issue on 7th March, 1941, with 100,000 guns ordered.
How did the gun become known as the ‘STEN’ and what did Sten stand for?
We know that the ‘S’ stands for Shepherd and the ‘T’ for Turpin, but what about the ‘EN’ – it is generally accepted to represent ‘Enfield’. Why? Because RSAF Enfield is synonymous with British military firearms. Additionally the Bren light machine gun’s name is a portmanteau of ‘BR’ from Brno, the location of the Czech factory the zb.26/30 originated from, and ‘EN’ for Enfield, the British factory that anglicised the design for British manufacture and service.
Enfield, however, wasn’t where the Sten was designed. Turpin and Shepherd claimed that most of the work on the design had been done out of hours. Additionally, during the winter of 1940, the Armament Design Department was relocated, from Enfield to a former Drill Hall in Cheshunt, Hertfordshire to escape the bombing of London.
While the Sten may not have been designed at Enfield, the first prototype was partially assembled there with work also done at Turpin’s own home workshop. A further 46 pre-production pilot models were later ordered from RSAF Enfield, in February 1941.
Intriguingly, early accounts suggest that ‘EN’ may have stood for ‘England’ – not ‘Enfield’. In October 1942, the fifth instalment of ‘Know Your Weapons’, a semi-official series of weapons manuals printed by the publisher Nicholson & Watson, explains that ‘EN’ did in fact stand for ‘England’.
In June 1943, Turpin penned a semi-anonymous article for ‘The Model Engineer’, about the design and development of the gun, which repeated this claim. An October 1943, article in the US Popular Mechanics magazine, entitled ‘Machine Guns from Backyard’, includes a supposed quote from the inventors explaining that the “E and N stood for England.”
A more official account came in June 1949, at a hearing of the Board of the Royal Commission Awards to Inventors (a board set up to reward inventors who had done important war work). One of the board members Lord Justice Sir Lionel Cohen asked Shepherd: “Why was it called the Sten?” The colonel replied: “It was called the Sten by the then Director General of Artillery. The ‘S’ was from my name, the ‘T’ from Mr. Turpin, who was my draughtsman and who did a very large amount of the design, and the ‘EN’ was for England. That is the origin of the name, for which I accept no responsibility.” This suggests that the ‘EN’ standing for ‘England’ may have originated from the upper echelons.
Sadly, there was no officially published explanation of the name as official manuals rarely go into superfluous detail. In 1948, however, Ian Hay published R.O.F. The story of the Royal Ordnance Factories, 1939-1948 in which he stated the ‘EN’ was a reference to the Enfield factory. Similarly, another early published account, D.M. Ward’s 1946 The Other Battle, a history of BSA, also suggested it represented the factory name.
In truth it is difficult to know exactly what the ‘EN’ stood for. It may be that both Enfield and England were discussed and used by various individuals and offices. There may have been an element of propaganda to including ‘England’ in a weapon’s name which led senior officers to push this in the press and direct the gun’s inventors to suggest this was the case too. Of course the authors of those earlier books may have mistakenly believed ‘EN’ stood for Enfield, as it does in Bren. Personally, I’m inclined to follow the primary sources attributed to the two men responsible for the design, and believe it initially stood for England.
Shepherd was awarded an OBE in January 1942, and became the Assistant Chief Engineer Armament Design (A/CEAD), he was promoted to Lt. Colonel in August 1943. He retired from active duty at the age of 55, in January 1947, and was removed from the reserve list. He was granted the honourary rank of colonel. He died in April 1950, aged 58. Turpin retired from RSAF Enfield in 1953, and died in April 1967, aged 74.
Beyond a pair of discretionary payments, £1,500 to Shepherd and a small payment of £200 to Turpin, neither man was officially rewarded as they were deemed to have essentially done what they were paid for, designing small arms. Scant reward and recognition for a weapon which became one of the key wartime small arms of the British and Commonwealth forces.
Our thanks also to Jonathan Ferguson, of the Royal Armouries, for sharing his thoughts on the ‘Enfield’ vs ‘England’ debate.
The Sten Machine Carbine, P. Laidler, (2000) R.O.F. – The Story of the Royal Ordnance Factories, 1939-1948, I. Hay, (1949) The Other Battle, D.M. Ward, (1946) The Sterling Submachine Gun, M.J. Moss, (2018) The Sten Gun, L. Thompson, (2012)
‘Sten & Bren Guns’, Know Your Weapon #5, (Oct. 1942)
‘The Sten Carbine’, Model Engineer, 3 Jun. 1943, H.J. Turpin Board of the Royal Commission Awards to Inventors – 1946-49
‘Machine Guns From Backyard’, Popular Mechanics, Oct. 1943
During our first research trip last spring I had the opportunity to examine an unusual ‘hybrid’ Sten submachine gun. The weapon combined a MkII Sten’s receiver with a MkIII’s magazine housing. Added to this was a proprietary folding stock and a new fire control group and pistol grip.
Very little is known about the hybrid Sten with Peter Laidler’s book The Sten Machine Carbine mentioning it and the later Osprey book by Leroy Thompson sharing a photograph and brief caption which calls it an “experimental version of the Mk III.” It is also unclear exactly when it was built.
Below are some photographs I took of the Sten, lets look at some of the interesting features of the Hybrid Sten.
No production Variant of the Sten was fitted with an under-folding stock, the Australian Austen, however, directly copied the MP38/40. The entire weapon is covered by a layer of textured, crackle paint finish, this was commonly used on commercial Sterling Mk4 submachine guns. The weapon has a short, 3.5 inch, perforated fore-end welded onto the front of the tube receiver that appears to be from a Lanchester.
The under folding stock is rudimentary but effective, the butt plate swivels free but the lock up is quite secure. It uses the receiver main spring-loaded return-spring cap. The folding stock attaches to the pistol grip assembly (which can be seen detached below).
The proprietary rectangular trigger group housing brazed onto the tub receiver is unlike any other Sten and lacks a fire-selector.
The pistol grip itself is made from paxoline, a form of early resin plastic. The shape shape of the pistol grip does not resemble any production or prototype Sten grip. A simple hand-stop, made from a bent piece of sheet metal, has also been added in front of the weapon’s ejection port to prevent the user’s hand moving back and fingers being caught if gripped by the forend.
While the origins of the hybrid Sten remain unclear I don’t believe it was an officially made prototype. While impressive it is relatively crudely assembled and does not match the Sten prototypes made by Enfield, such as the VI. Intriguingly, the magazine housing of the weapon has been stamped ‘PILOT’ below the usual ‘STEN MkIII’ stamp. I suspect that the weapon may have been put together by a unit armourer, perhaps authorised by a superior officer to suggest improvements or as an unofficial project gun.
UPDATE: Their is some evidence emerging that this Hybrid Sten may be related to the T42 Sten prototype, part of the Sten MkIV development program. Where this hybrid fits into the story is not yet clear but the similarities are striking, when we have more information we will revisit this weapon.
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