The old SMGs - did they fail often?

sulisa

sulisa

CGN Ultra frequent flyer
Rating - 100%
52   0   0
Location
Eeeeesst
Hi folks,

I was reading a thread a couple days ago about an SKS that was "firing auto" (you've read these from time to time) - a stuck firing pin, or something. Dangerous, with a chance of an out of battery primer strike.

So that got me thinking... when I first joined the Reserves, we still had a couple SMGs (Sterlings?)... When you look at the design of these and other blowback SMGs, like STENs, they were basically a heavy bolt assembly, held back against a spring by a trigger, which when released stripped a round from the mag, chambered it, and fired it. The bolt assembly was heavy enough that the pistol round would have expended most of its energy by the time inertia got that bolt assembly moving backwards, and had just enough oomph left to shove the bolt assembly rearward past where the trigger would catch it, extracting and ejecting the spent casing along the way.

If I picture this bolt assembly as solid, with a pointy pin on the front end, isn't there a chance that a bullet, caught on something on the way to the chamber, could have gone off? On the modern firearms, there's all sorts of sears and timing devices to prevent the firing pin from striking until the bullet is chambered, but was there any insurance like that on these older ones? Or, put another way, how did this fire the round at exactly the time the bullet was fully chambered. Surely there was no thought to "timing" on these old warhorses?

Am I missing something in the design, or have I just never heard of range accidents or wartime incidents of guns blowing up?

I've always been a fan of the "simple is best" theory, and love bolt action, but this mental distraction has survived a couple days, and a couple Internet searches, without an answer :)

Thanks
 
From what I know, the problems related to the sten and mp38/40 were magazine/feed related issues. Once those were sorted out, they were a good piece of gear. The sten also had a poor safety record, as a good knock could cause it to fire un-expectantly. I believe the first safety was a simple notch that held the bolt open, smack that, and BANG! The open ejection port could allow crap into the gun, but it would work well without lube, so sandy environments were no problem, if run dry.

I think the sten is amazing. What is there, I think 47 parts to the gun?
 
The Canadian version of the Sterling had one extra safety feature over the old sten in that the trigger mech would hold the bolt open or closed (wherever it was at) if the selector was on safe.

The fixed firing pin caused detonation of the primer just before the cartridge was fully into the chamber. This way, the recoil was taken up by both the forward momentum of the block as well as the spring. There were explicit instructions not to fire the SMG C1 by putting a round in the chamber and then allowing the bolt to close onto it.

Back in those days of the glass beer and pop bottle with no twist off caps, the mags were often abused. How they functioned at all is beyond me. I do recall the odd round going off in the tube rather than in the barrel, but it was not common. Seems to me there were instructions that left handed shooters were to correct their abnormal ways and fire the SMG C1 right handed, so their face was on the "safe" side of the gun.
 
LOL Sten - "the safe side"

I hadn't thought of that - there would be a tiny period of time between primer strike and the round going off, so the momentum of the bolt assembly (probably not the right name for it), would actually be still bearing down on the base of the round.

I remember the rumours that a good smack on the end cap would fire it - I guess that would cause the bolt and spring to compress, taking the pressure of the trigger, which could also depress by its own weight, and the bolt could ride forward before the trigger could catch it.

Was the firing pin actually fixed to the bolt?

I only got to fire the Sterling on one occasion - from the hip, hunched over slightly, left hand (I think) was holding the barrel shroud, to compensate for muzzle lift. Short bursts, after a couple trigger presses, the snow was kicking up *near* the target :)
 
The pure simplicity of the gun is what amazes me. It's amazing it works. I think, it is the eternal smg, as it will always be the design turned out of basement factories in times of trouble. Fence pipe, springs, a little machining, a home made barrel... the mag looks like the tricky part...and voila!: one smg.

http://w ww.milsurps.com/content.php?r=422-Blueprints-for-The-STEN-MKII-(complete-machine-plans)

Easier to make than anything but a single shot shotgun.
I can imagine it would be a little depressing to be issued one in war though. "Seriously, the other unit gets Thompsons, and we get these things? Did we do something wrong? It's the drinking, isn't it?"
 
If you were not following approved procedures, it was possible that you might be able to hit the back end of the gun, have the bolt come back far enough to pick up a round but not be caught by the trigger mech sear, and then fire the round. And the odds of hitting the gun hard enough to just do what was described are slim. Just as good a chance of catching the cocking lever on your combat shirt pocket and effecting the same thing. But if your safety was on, then you were fine in either of the instances listed above. And if it did fire, it was only going to fire one round...the recoil from that one would force the block back far enough to catch the sear.

I have heard some of the ex-servicemen from that era regurgitate the old sten myth that the gun would go off, and spin round and round until it was empty. Scientifically impossible and utter BS.
The Cdn sterling had a simple one piece bolt with fixed firing pin which was more akin to the sten. It was reliable enough. I am not certain if the one piece bolt was just to simplify production or escape the licensing fees from sterling. Sterling's bolt was two piece and with a double spring affair. We made a number of changes to our gun from the British version. Some of the changes were good (bayonet lug for a FN bayo as opposed to the Brit's retention of the jungle carbine bayonet for the sterling) and some not so good (stamped mags without roller platforms, cheaper stamped trigger mech as opposed to the stainless steel sterling trigger mech). Most components or sub assemblies would interchange with the British version though.

Your hand should have been on the shroud. Holding onto the mag was a no-no. I have always found the sterling to be reasonably accurate to 100 yards. Of course, the gun can only be as accurate as the shooter operating it.
 
LOL - I wonder how popular it was to "trade up" in battle. Look at the "Call of Duty"s out there - as I run along, I'd pick up anything that looked better than what I was carrying. I could just imagine in real life, after the battle "Where'd you get that?" (found it), and "Where's your issued rifle?" (left it back in the field, where I found this!)

Look at how complicated an AR is - with locking lugs, gas powered force one way on the bolt head and the other way on the bolt carrier to "unlock" the lugs - it's genius, but so many moving parts, and so much machining! Then, the SMGs, if we could use the round detonation to push back the bolt until there is a trigger in the way... yep, a classic.

Thanks for the plans link - fun to see how they went together (we'll never see these in use again, sadly).
 
There are, of course, some 50 or so of the semi auto sterling mk4 police carbines floating about Canada. They are restricted only, and other than the disappointing 5 round magazines, are a real hoot to shoot.

You can forget about those inexpensive semi autos down in the US. They would likely be classed as prohibs, due to their close mechanical relationship with the prohibited closed barrel sterlings (and variants).
 
... and that's the downside to the simplicity of design - simple to modify = prohib. Yes, I remember the "keep your hands off the mag" rule - I wonder if it might have been to prevent hitting the mag release button... disrupting the feed path would have the be the only logical reason (except for accidents).

I know precious little about the Sterlings, and appreciate you guys passing along your knowledge and memories (and adding it to the semi-searchable record that is CGN :)

I was looking at that web link, and there's a photo album just under it with some computer-drawing and up-close photos. Ah to have been an inventor during the War... nothing pretty at all about the Sten, and that to me makes it even more appealing. Although the SMLE #4s were a work of art, and I owned two of them, so my tastes are all over the map :)
 
I was on a range once with a semi auto CA Sten being fired. A gent had loaded up some 9mm rounds. When he tried them in the gun, they would not fire. Just clank, clank.

Why? On examination, he had roll crimped the bullets as he had a 3 die set vs 4 die set with taper crimping. It was basically revolver ammo.

Thus, the rounds were not headspacing in the chamber properly. They'd go in too deep and beyond the reach of the firing pin I figured. Thus the API thing (advanced primer ignition) that I read about for the Sten...was questionable. If the round actually went off before the bolt had ceased forward motion, then why wouldn't his ammo fire?
 
I never had a problem with Sterlings, I did have it double once. The only stoppages were not pushing the mag in far enough. A good old-school SMG has very few problems, apart from drop-safety. My mate shot his car with a Sterling, the seatbelt caught on the cocking lever.
 
As was said before, mostly mag problems and that was due to the mag lips being bent. In snow, if you dropped it and some snow melted onto it, the water did tend to freeze the bolt in place. If the spring froze up as well you would turn it and dump your mag into the snow as well. Always liked that SMG regardless.
 
API and crimping... interesting - yes I could see if the round was being pushed by the bolt (and in part by the firing pin), then the round abruptly stopped upon hitting chamber dimensions, then the firing pic would continue into the primer to touch it off. Now where 9mm is rimless, how it was reloaded/sized could make the difference. Being a tapered case, if it was full-length sized too small, it could seat farther in, unless the case lip hit something, or the bullet hit rifling.
 
The prohibiting of the closed bolt sterlings was not because they were simple to modify...they weren't. They are still acceptable in the US, where the BATF is not keen about easily modifiable weapons either.

They were banned because they were listed in the guns digest as being commercially available and they looked military. Many other guns were prohibited for the same cosmetic reasoning.

The sterling's lineage can be directly traced to the German Bergman SMG and through the Lanchester SMG. Two British engineers were tasked with the reverse engineering of a seized Bergman for the British military to use. It was obviously a heavy and somewhat expensive gun. The two engineers re-designed a much cheaper and lightened version known as the sten. Meanwhile, the Sterling company, who participated in the production of the Lanchester, redesigned many features of the Bergman/Lanchester into the Patchett, which was very similar to their later Sterlings.
 
Some good basic Wikipedia articles on the the Bergman and Lanchester (a direct copy of the German MP-28) - heh, if you don't have time to design one, copy another!

Interesting to see the mags sticking out the right side. With the Sten and Sterlings, we know the value of retaining control with the firing hand, while ripping out and replacing the mag with the other.

It mentions the later Lanchesters were modified for select fire. I can imagine making a full auto (like the Sten) would have been easier than making a semi, and certainly a select fire. I like the wood on these, and the ergonomics look better. The grip on the Sten looks brutal (I can't imagine anything looking worse, actually :)

From the design of the Sten, I could see folding stock options could have been designed fairly quickly, since the "stock" is a dead piece of metal rod. Did it ever feature a folder, or removable stock, that you've seen?
 
There's a Youtube video about Sten production. The original design was done by a guy in his kitchen. The army approved it but demanded it be even simpler. When the design was revised, they took the drawings to a toy company that was going to be tasked with producing it. The owner of the toy company said "that's not how you build that, here's how" and he made further revisions that made the Sten easier to manufacture.
 
Early Lanchesters were selective fire; later ones were auto only to allow a simpler trigger mechansim.
All Stens, except for a few silenced ones, were selective fire.

If anyone wants to learn about Stens and Sterlings, and not just recycle stories, get hold of Peter Laidler's "The Sten Machine Carbine" and "The Guns of Dagenham".
 
it was a decent design, except for the stock which was far more dangerous that exploding bullets. Nothing like having your fingers pinched in minus 15 when trying to fold or unfold the stock. Also the bloody cocking handle would dig into your body. I prefer the UZI design with flat sides and easier to carry. I also found it quite accurate and reliable with good mags.
 
You must log in or register to reply here.
Back
Top Bottom