The Sten Gun

I fired a Sten and a Tommy in the Home Guard and RAF. Tommy did fire high right. But was taught that the Sten was a carbine (ie no rifling) which accounted for its inaccuracy. Carried one in the cab of my workshop vehicle for four years from Normandy to the end of hostilities in Germany. But never had to fire it in anger, thank Goodness! Recall being told by F/Sgt Instructor to watch out for the fingers of the left hand as some people lost them if they encroached upon the right hand ejector port. He also said that whenever you picked one up you should "take safety precautions, just as you would before taking a young lady out"
Les

 

Doctor D
But was taught that the Sten was a carbine (ie no rifling) which accounted for its inaccuracy


The Sten like any other SMG had rifling. Right twist 1/250 6 grooves at 2.5mm x.22m depth. fairly standard contempry machining.

It might take awhile but I'll try to address some of the Sten myths

It is noted for malfunction, the major cause of malfunction was that it was rapidly introduced into service. As a weapon primarily for NCOs and specialist- (ie Radio men, tank crewmen and other trades, unlike Soviet Union the Britsh did not have SMG sections) the Sten probably got more TLC than it required, if oiled it would readily pick up dirt,grit and sand (Post War Sterlings had muck grooves in the bolt). If the Sten was left dry or dry lubricated (powdered Graphite) it worked fine.
To emphasis how bad overoiling a SMG can be- it was a standard test for experimental SMGs in the Soviet Union.

Originally Mk1 and Mk2 (major model) was designed with a sleeved magazine mount that turned to close the receiver during transit, this seems to have been eliminated before issue, as it could cause the magazine to misalign. In the MkIII the magazine mount was simply welded directly to receiver. It did however mean that the weapon had open magazine and ejector ports, meaning that care should be taken to prevent ingress of sand etc, by normal accepted methods.

The magazine was a persisitant problem, manufactured of light gauge steel it was easily damaged both in its body and mouth, the spring was Ok but as in many auto magazines loading a few rounds less than a full load was a good idea. The Russians had the same problem of light gauge steel box magazines in both PPSh41 and PPS43 SMG they resovled it by increasing the gauge from 0.5mm to 1mm.

Training, because the Sten was manufactured and issued in a crisis users had to learn as they used it. The stance often seen in the moovies in holding the magazine was a realy bad idea, the approoved stance was gripping the receiver extension forward of the magazine, this lead to the finger problem meantioned by Doctor D. in that the little finger strayed into the ejection port- this would only happened once it should not happen at all as there is a limit stop (lug) forward of the port as shown in the two attachments to prevent this as shown in the two attachments- I assume some may have been issued without it as this story is almost a Firearm Myth, originally the edge of the magazine sleeve acted as an edge to abut the finger.





Other things it was cheap yes, there is a story but without accredition that the material cost of the Sten was 6/8d in old money about a manual workers shift rate in 1939 -that's 33p -under 50c U.S.

I first came across them in the Cadet Force (along time ago) and we had some odd models, one had a through charging handle which allowed locking out of the bolt when closed (ie bolt forward)- but I think this was a trial model on a Mk2 and survived as a DP weapon.

I fired one once (2mags from a MkIII) after a Sterling requalification shoot. it was really good on par with the Sterling in semi-auto mode, with consisant grouping hits. Like any SMG apart for house clearance the auto mode is just to tell the enemy to *** ***.

Other models

The Lanchester was a modified MP28-II (based on the Bergmann MP18 of WW1 origin) by Sterling Arms Co. It was only used by the Navy, was very expensive and may have had problems certainly later models eliminated the semi auto mode.

The Welgun 9mm was designed by BSA possibly for SOE use there is conflicting reports whether it was purely an experiment


EMCM 9mm with its telescoped bolt and grip mount magazine- rather like a UZI.
View attachment 18598

Steve

 

I´ve seen shooters hold the Sten by the barrel-guard (if it can can be called like that ) and the magazine while spraying; which way was combat-better?

Also, how is it, if supposedly the gun had such shortcomings, that the design just kept on going up until our days, in the shape of the Sterling? I do love the shape, with the side-mounted clip.

 

Yeh! Razin, I clearly remember the guy using the term 'Sten Carbine', in 1940, but I'm not questioning your obviously superior knowledge of the subject matter, just his! For, as a Radio man a few years later, I recall looking up the spout after pulling it thru' and noting the rifling. I just thought they'd modified it in the intervening years. The one I carried around was the one you show as a Mkiii. I was never an armourer. Cheers Les

 

My Dad drove an armoured car so the logical crew personal weapon was the Sten. I seem to recall my Dad thinking it was generally OK but had problems, particularly with its spring. Apparently there was a risk that if you dropped it butt first the impact could cock the sten, not lock the bolt so the upward return could fire off a round.
Jim

Similar from my Grandfather who was RAMC and did a fair amount of patching up of clumsy sten users. He also recalled how if it was knocked over from being propped against a wall or similar, it might often fire off a round.

 

DoctorD don't worry about it I was told a load of rubbish at times, I once got a thick ear from a corporal, first for not taking notice of what he said and then repeating his idiotic error back to him- course he denied it, but everyone else had heard it- but it's not democracy and everyone get things wrong sometimes hence my correction of my big post, I have really got to use word and then transfer it to this dialoge box then I can get rid of stupid errors before I post.

With the old valve sets a MkIII would be the best for weight saving a thompson would have been a bit of pain.
regards

Steve

 

WotNoChad
He also recalled how if it was knocked over from being propped against a wall or similar, it might often fire off a round.


The partial feed was a problem with many SMGs the German one would do the same, oddly enough the Russian ones like PPSh41 and PPS43 the saftey prevents it, but I've never used one and I don't trust safetys anyway. Of course clumsy tends to follow exhausted then dead sometimes.

I reckon the push through cooking handle modification was meant to stop this, but apart for the single DP weapon I never found another with this that worked (however I've only seen about 15 or so), they must have been ground down to prevent it use and the MkIII didn't seem to have it at all. I think that it may have been eliminated as it could operate on its own stopping the weapon, probably a good idea but requiring more time something there was not much. A ball and spring indent might have done it, but again complicating things in some way maybe the Russians had it right.

~Steve

 

Warlord

The proper way is the "army way" I've had a look around for a photo of a shooter firing one -its remarkable how it is impossible to find anything at times however I find one of a shooter using a Sterling L34A1 instead of the forearm grip think holding the standard barrel sleeve.

It would be possible to fire from the hip with the forehand on top of the receiver extenson-barrel sleeve to prevent the weapon rising in auto mode. alternatively holding the magazine well with the index,2nd finger and thumb, but avoiding griping the magazine itself with the other fingers is also possible.

Hip shooting is not an aprooved method.

~steve

 

I remember with the F1 SMG we were taught to place the non trigger finger hand on top of the barrel surround and to lean over the weapon to prevent the barrel rising when fired from the hip.

 

was taught that the Sten was a carbine (ie no rifling) which accounted for its inaccuracy.

Nope. A carbine is short rifle. I am surprised that you didn't see the rifling when you cleaned yours.

Second Stens are not inaccurate but they are a short range weapon. This is due to the VERY short barrel. (Under eight inches.) In fact the German word for SMG is Machine Pistol (translated to English) - a much more accurate description in my opinion.

 

In the IVth Hussars we had Tommy Guns rather than Stens.

I looked in both the Regimental and my personal diaries for any mention of the Tommy Gun and found the following items:

Regimental Diary:
A 4th Hussars party was organised consisting of Lt WK Hedley and Sgt Sowler armed with Tommy guns, with K and his friend. On reaching the top of the peak, K went ahead to the hut. Sgt Sowler went to the back of the hut and Lt Hedley entered through the front and both men, though armed, surrendered without a struggle. The second man proved to be Kreis Propaganda Leiter Freidrich Plob. They were arrested and taken to prison at PATERNION where they were held until taken over by Capt Willett


Personal Diary
Tuesday 24th. April 1945
Flap in the night and we moved off at 2 am. XXXXXX was blotto and consequently net was lively. Made sweep of Ferrara suburbs. Busty smashes door in.
Wednesday 25th. April 1945

I subsequently described the event in the BBC Archives as follows:

This episode about Busty was a piece of pure ‘black comedy’.
The squadron was advancing Northward, and in the middle of the night of the 24th we came across a small farmhouse. Busty, Tommy Gun in his hands,very melodramatically kicked open the door of the house then, as no-one was in residence, rummaged through a chest of drawers.
He found and ‘liberated’ a tweed suit saying ‘this might come in handy later for a bit of swapping’ . The next day we were at another farmhouse where the occupants gave us a bottle of vino and Busty promptly gave them the suit he’d ‘liberated’ the previous day. I couldn’t help wondering at the time whether or not at some time in the future farmer A would see farmer B and ask him ‘Where did you get that suit from, I used to have one just like it !’

 

Beerhunter
Nope. A carbine is short rifle.


The term Machine Carbine was used by the British for the SMG type weapon early in WW2 possibly because some of the commercial SMG from the U.S. were similar in appearance to a carbine (when the mag was not fitted look at a Reseiling M50 for an example). Further it is likely that the term carbine was used in the U.S. prior to 1941 to differentiate between military service weapons, SMGs, and Police weapons (carbines).

We have to take on face value what DoctorD was told by his drill instructor,-in the army you get told all sorts of BS and it is surprising how it sticks.

For all we know some early weapons may have been produced without rifling and of low grade materials only as Demonstration Purpose (DP) pieces which were never meant to be fired. All operative Sten had rifling. Machinery existed in U.K. facilities for 9mm rifled barrel manufacture prior to WW2, however it is possible that the Stens were amongst the first swadged barrels in U.K. weapons.

~Steve

 

The term Machine Carbine was used by the British for the SMG type weapon early in WW2 possibly because some of the commercial SMG from the U.S. were similar in appearance to a carbine (when the mag was not fitted look at a Reseiling M50 for an example). Further it is likely that the term carbine was used in the U.S. prior to 1941 to differentiate between military service weapons, SMGs, and Police weapons (carbines).

My point about carbines is that a carbine is a short rifle, not an unrifled weapon.

I know that the Sten was called the Sten Machine Carbine. Possibly a better term than the American 'Sub-Machine Gun' or even the German term.

Oddly enough, the Jungle Carbine, which by most definitions is a carbine, was never officially known as such but rather the Rifle, No5.

By the time we got around to calling SMGs SMGs there were indeed used as the carbines of old e.g. drivers and others in non-infantry roles.

 

In catching up on this thread I thought I would add some pointers I've read about and also learned from a couple of long serving armourers.

The turning magazine housing ["mount" as some people call it] on the Mk2 Sten was not eliminated before issue, indeed the resistance found it useful for concealing a loaded sten flat under a coat etc. I owned a mid production Mk2 and it still had this feature intact.

The little finger problem was initially overcome on the Mk2 by producing a small clip on ring with a finger guard which slid over the reciever at the forward end once the barrel nut was removed. Later on there was the riveted on finger guard.

The locking action of the cocking handle to lock the bolt forward by pushing it in to a locating hole in the reciever was initially a field modification done by armourers to a spec sheet [I have a copy] - also issued in SATS I think. My Sten had this feature. Later on they were done in the production process.

It was almost certainly done to prevent the firing off of a round accidentally. It has been proved by a senior armourer that dropping a cocked Sten with the safety off from a height of about 2 feet can result in a single round firing. Of course, when the blot cycles back to rest it cocks against the sear and will not fire again. It should not fire off a burst or a whole mag because of course trigger pressure is required to be maintained in order for the sear to be out of the way.

In the opinion of armourers I have spoken to this may have happened due to another fault with the firing mechanism or if something broke when it was dropped. However, I have read and heard many many ex squaddies from WW2 and the National Service era swear blind that they heard of it happening or it happened to them so many times its unbelieveable now. As memories fade I think its a case of something they heard becoming "fact" in their memory. I'm certainly not saying it didn't happen, but that the frequency with which I have heard it would surely have led to it being withdrawn.

Funnily enough if I ask them whether they were put on a charge for having their Sten cocked and off safety when regs strictly stated it was to be made "SAFE" they go curiously quiet or wander off.

The problem with the magazines lies mainly in the feed lips and keeping them from damage. There was about 40 million mags made during WW2 according to my contact who still worked on them in the 1960s. The single position feed mag caused a lot of trouble.

 

I'm adding a quote here from my armourer friend who sent me this a while ago. It details some of his experiences with the mags and the trouble they went to to keep them in good shape!

Magazine 9mm. Sten M.C. came either 10 or 12 to a box. Not only in a box, each magazine was individually wrapped in greased paper with tie on label giving description. 10 or 12 were then packed into a strong cardboard box which was wrapped in thick brown paper which was in turn then wrapped in pitched strong paper that was dipped in molten pitch to seal all the joints. This was then overwrapped in thick brown paper with a label showing contents. This lot was W.D. standards that if said box fell into the sea, the contents must be perfectly preserved for up to 5 years. Great joy for me as a swimmer that resembled a brick made from lead.

Anyhow, we unpacked these new magazines, threw all that wrapping aside and began our inspections. Each magazine was stripped and cleaned. Each mag. was inspected for any burrs on the feed lips. These were cleaned and polished. The mag. was re-assembled, filled with 10 to 15 drill rounds and tested for height of feed and 8 degree feed angle. These measurments were critical. Most out of the 10 or 12 needed adjustment. We then filled each mag. with 30 rounds prior to a range test, took ANY Sten from the rack and test fired each mag. In spite of all this, at least one out of the box full would give bother. After further adjustments, if it still gave bother, we stripped it to a casing, put it on the anvil, smacked it with a hammer and backloaded it through the QM. for a replacement.

What if you didn't have a wonderful armourer who had joined RAOC in 1940 and transfered to REME in 1942 ? What if you were a Resistance fighter/Airbourne/SOE/Aux-Unit/anyone else who was issued a Sten but nobody had bothered/had time/dropped as issued magazines that you loaded, put in your Sten and pulled the trigger, to have that trouser filling clunk instead of a burst ? (2 to 3 rounds in the British Army, 32 for the Americans). Yes, you would blame that blasted Sten.

Well, we almost never had a stoppage with Sten, just as we almost never had a stoppage with Sterling which has a superb, world beating double feed, roller platform curved, ribbed magazine.

Why does it feed from the left ? Well, for those who have never had incoming, there is a great desire for the earth to open up and let you drop into the gap. Left hand feed not only allows you to hug mother earth but it makes feed from mag. to gun so much easier. Those foriegners who have underslung magazines like the Germans/Italians and most others are truly giving gravity a dreadful time having to push up 32 rounds or however many whilst having to lie prone above magazine, gun and eyes. Thats a lot on show. The Australian Owen has the best feed position, vertical on the top. I have taken base plate and spring out of an Owen magazine and having a mate to dribble in rounds, have sustaned automatic fire that would have done justice to a Vickers. Left mounted magazines enable the firer to cradle the mag. on the left forearm making it easier to handle.

However, although the mag. housing was fastened to the left by 4 drive rivets on the Mk.1&1* and spot welded on the Mk.3, because the Mk.2 was developed for Airbourne use, to have a captive projecting mag. housing could have produced serious injury when landing, taken valueable container space or made it harder to hide for clandestine use, this housing swung down through 90 degrees to aid compactability. It was NOTHING to do with sealing out dirt and dust, the cocking slot allowed plenty of space for that however, the Sten fared outstandingly in dust mud and grit trials, unlike Thompson and especially that tin disaster, the L85(SA80).

What about "Went off when you dropped it"? Not something to own up to. In capital letters in the Sten Machine Carbine manuals it is clearly written, "This gun must NOT be carried with loaded magazine and breech block FORWARD".

Before anyone mutters about the Sten, the famed so miss called "Schmeisser" MP38 & MP40 (they had nothing to do with Schmeisser) along with most other carbines had exactly the same problem. Most forces adopted some sort of modification to lock the breech block in the foreward position during the war.

We introduced the push through cocking handle in 1943 to lock the foreward block. However, inertia COULD set the breech block back far enough for the block to get behind a round in the magazine, in that case, it would go forward, chamber and perhaps fire that round. Perhaps ? Certainly only one but the resulting short stroke would normally give a miss-fire, just before the RSM stuck his pace stick through one ear and out of the other before sending you on a helicopter simulation course !

This malady has always affected "blow back" guns like the Sten/Sterling/MP38 etc. The sear that holds back the breechblock is much further forward than the breechblock is blown when fired. As these guns are initially fired "off the sear", normally against a full magazine with all the pressure that results, just when a full stroke is needed, the block is driven forward a short distance off the sear, often resulting in a jam.

To overcome this, on demonstrations, we pulled the cocking handle fully to the rear, pulled the trigger and let the handle go. Never a problem. However,a smack on the butt plate could do one of three things. (1) It sets back but doesn't go far enough to get behind a round, it goes forward harmlessly. (2) It goes back just far enough to get behind a round, that would perhaps chamber and perhaps fires the round but please note above. (3) It goes back too far in which case, the sear will hold it to the rear in the cocked position. The options are thus three fold but with ALL blowback guns without a breech block lock the same applies, NEVER carry such a gun with the breech block forward with a loaded magazine fitted unless a forward lock is fitted and applied. Colchester Glasshouse was full of folk who thought differently !

 

The chap we bought our house from in France was quite happy with his sten gun!! He told me he 'picked' it up in the street after the invasion. He also has several other guns which included a German Mauser and a lee enfield. The prize was a Luger, complete with holster and spare magazine. They are all still operational too. He said that half of France has a collection of these weapons and he knew of one chap in Normandy who managed to get a Tank into a barn!!! Anything, apparently, was there to be 'picked up' if you wanted.

 

The WW2 Sten was an abortion. A real dogs breakfast of a weapon.Welded construction.. In old money 6/11 and three farthings, just under seven shillings to make. Finger or thumb chopper. Lucky to hit a barn door with it. I put mine on the ground and it burst into life parting my best mate Harry's hair ...genuinely.

I have a photo somewhere of me holding a Sten, when we were at the lost village of Tyneham in the Purbecks, while giving a live bit for BBC TV.

Sapper

 

They did the job intended! Made in a time of extreme austerity they are a design of theirs times. I think they've been maligned too often. Actually far from being assembled poorly the manufacturing tolerances were incredible.

As I have been told: for example, the sear bent on the breechblock was ground to 12 degrees, 50 minutes. Tolerances ? None. That would affect the trigger pull !

The blocks were shadow viewed on a screen to check tolerance. Two tenths of a thou. here, plus or minus two thou. there ? Yes, normal.

Why ? For that answer, we need to look at assembly. (not component manufacture).These guns were assembled mainly by unskilled labour, most female, many straight from the Employment Exchange. They stood or sat behind two long benches, both facing a central conveyor belt, trays of components in front of them. They were fed bare action body/trigger mechanism assemblies that went slowly up the belt. They, working either side, took these bodies off the belt, added their component from parts delivered in metal or wooden trays before replacing on the belt for the next assembler. By the time the gun reached the far end, it was complete (in Mk.2 form) apart from the foresight. A gauge was put down the muzzle and backsight aperture and the barrel turned until "run out" was minimal whereupon the top of the barrel would be marked with either with a line or the last 4 digits of its serial number on the top of the muzzle so that the barrel could be removed and replaced without losing zero and the correct (out of a choice of 3 heights) foresights would be selected and fitted, later to be welded into position to preserve location.

The lady who "adjusted" the front plate of the Stock, Butt to ensure minimal side play whilst still being easy to remove/re-fit the butt was the only person to have a special tool (a hammer!) apart from another with a heading tool to rivet the trigger stop pin in the trigger mech. housing. What can we conclude from this ? The components had to be within so tight a tolerance that nothing interfered with rapid assembly on these lines.

Competition was fierce between one line and another and there was no ability to do any filing, adjusting or anything else. The shifts vied to make the most number of guns in their alloted 8 or whatever hours.

All the parts had to fit exactly so there was nothing to do other than assemble those 60 odd parts. This meant not only the masses of component manufacturers had to gauge regularly their components, the viewers had to re-check them before those components were delivered to the assembly factories and they in turn had to re-check everything before trays of parts were handed to the assemblers.

I hope this has been of interest to you folks interested in the Sten.

Sapper, with no disrespect to your own personal experience, there are far too many stories I have heard repeated again and again. Simple answer to you putting yours on the ground, you should have pulled the cocking handle back into the safety slot or engaged the cocking handle in the forward lock position, especially if you had a loaded mag on it. Yes, it may have parted your mates hair but who's fault was that? Was it the tool, or the user?

Yes, welded construction. How long would it have taken to make as many, say Lanchesters, as compared to the Sten. Yes it was cheap, but could we have really afforded 3 million Thompsons in the pre lend lease era at £50 each? Thats 15,000,000 pounds. And remember, we were a BAD credit risk. We had to pay the US for everything in GOLD, which we didn't have.
Regards
Matt

 

As a wireless operator my pw was the Sten. My pouches were so full of loaded mags I developed sores on my scrawny hips. Soon after we arrived in Normandy, because of the many accidents, a mod was carried out which allowed the bolt to be locked. Mags were recalled too as the wire springs failed under load. We were told one of the Sten's benefits was that as it fired a 9mm round there would be lots of them laying around because the Germans used that size, good thinking - eh?

 

Matt,

Firstly congratulations and thanks for such a tremendous series of posts. Your work is very much appreciated. have some rep.

On the subject of telling of soldier for not locking the bolt Im sure you'd agree that in the real world it just isnt going to happen all the time. Im not sure I'd would carry my personal weapon in safe mode if I though at any point I was going to get jumped or in any combat situation.

Best regards

Kev