Buddy hit the jackpot the other day and had 5 stamps come back at one time. 2 of which were a Sten MK2 and a GSL sten suppressor.

He brought it over to the house and was having issue with it ruining right off the bat.

With the GSL integral its ramming the nose of the bullet into the breach face, and more often than not its not firing at all.

When it does fire the cases are severely blown out like it firing out of battery.  And the semi selector does not seem to work at all.

SO where do we start?

He has over 50mags and was only using 3 that day so we will go thru mags and try them. Beyond that not sure what to do other than spring change.

Attached File


Attached File

I'd verify the selector works first by manually cycling the bolt to ensure it's depressing the trip when set in semi. If it's not disconnecting, you may have a worn trip, or trip contact surface on your bolt

Sten magazines are very sensitive to feed angle......too little and the rounds will nose-dive into the bbl. as shown in your picture.....I believe the correct angle is 8-9 degrees

link to SAR article on adjusting them:

https://www.smallarmsreview.com/display.article.cfm?idarticles=1974

a few pics that might help:




Finally.....use hot ammo.....mine would runaway with 115gr value pack stuff...….loved Winchester Q4318 124gr NATO and anything hotter.

Don't use reloads unless you full length resize the cases

If that doesn't help, try it with an original (non suppressed) bbl......see if that helps.....I'm noticing that the bbl in your pic isn't quite flush with the face of the trunnion...….

Yeah I did the whole hand cycle with semi auto and no trip re set.

Also the mags he had on hand were the ones with brass inserts which reduced the capacity by half.

Does someone make a FA only trigger for the sten?

My only MG is a Mac11 so not familiar with what all is available for the sten.

And I also told him to trying switching back to the original barrel and working out the kinks from there.

To get the gun to work the mags had to be held up and forward to get it to feed if that makes sense.

To make it FA only, just cut off the portion of the trip that protrudes into the receiver tube when set to semi.....extra trips aren't expensive.....

Is the magwell perfectly horizontal when viewed from the front? Wear to the spring loaded pin or the hole in the receiver/trunnion that locks the magwell in place can cause the magwell to sag slightly......causing feed issues

Try an original bbl, and something other than those clapped-out Indian 20rd mags

The mag well does have some slop but not enough that it would induce a malfunction.

Also will swapping out the pin on the mag housing help get rid of the wobble?

Depends......it will if it's the pin that's worn.....if the detent in the receiver/trunnion is egged out, it wont make much difference.

As long as the bolt isn't dragging on the mag feed lips, it shouldn't be an issue.....

Ok thanks for all of the info first off.

I know one or two of the mags we tried had the bolt dragging across the feed lips.

I have sent my buddy a link to this thread so he may chime in. He is not all that active on this forum.

He also has some mag conditioning equipment on the way hopefully. The mandrel and the punch type set up not really sure of the correct name.

Not for trouble shooting... I wish I could help. But can we see pics of his gun?

As my good buddy says... "if the MG don't shootski, send it to Andrewski..."

Yep that discussion has already taken place. Think he is going to try the different mags and if that doesn’t work send it off to him.

He prices are very reasonable for what he does and in the long run think it will make the gun more valuable knowing he has went thru it.

I found that with my sten I just got I went and took 18 mags to the range loaded and threw 8 away with 2 that I think need new springs. Expect a 50-60 percent fail rate with the mags

Didn't the Indians reduce the capacity to 20 to improve feeding?

Others won't like me but for my m11 and the Sten Mk2 wilson tube setup..

the tapco magazines worked perfectly fine.

Another thing I did was get new springs for the rest of my STEN mags and they worked perfectly afterwards.

I can see that my old sten springs got a set into it.

Try new magazines or try new springs for them.

Hey guys, I'm the guy that was having trouble with the sten. This is my first mg and I am open to all suggestions.  I have around 60 sten mags that I need to try. Most of them need to be cleaned up as they have grease on the insides. That's why I only tried 3 that day. Feeling a little under the weather lately, so I dont know when I will get around to it. Hopefully soon.  I have read about those tapco mags from an article Frank put out and it made sense how the angle of the feedlips would stay more true to the 8 degree angle. I searched everywhere for them, but couldn't find any. I would definitely purchase some if available.  If a member here has 1 or 2 or however many they would be willing to sell I would gladly buy them.  Also if you know where to get them online please post a link.  I am gonna try all these mags first and see what I come up with. Will post updates as they come...
Thanks again

For everyone here FYI he caught the gay.

It happens when one gets 5 stamps back at one time and doesn’t take off from work to go enjoy them.

Just to clarify, it was 6 stamps, not 5. ??

And you should know your words are very hurtful and I am going to have to go find a safe space now. Lol

Hurry up and clean those mags so we can shoot this thing some more.

https://www.robertrtg.com/store/pc/STEN-MAGAZINE-SPRING-NEW-p6180.htm

buy 10 springs....

clean and change it....

Ordered today. Will change them out and see