Help needed with Bren mk II

Ok, this is my first post on these forums so I will try to keep this short. I am buying a Bren mk II and need advice, the receiver is a reweld and converted to semi auto, the welding looks pretty good, but the seller said he has had a problem when firing it. He stated he used cheap ammo and on some occasions the bolt has not gone all the way back to the sear and as a result kept firing, he is not sure if it is a problem with the bolt or something else? I am hoping someone can give me a few ideas of what could be causing the problem. I have already paid for the rifle but told him not to ship it until I know what might be wrong.
I thank you in advance for your suggestions.

THINK SIMPLE. There is only ONE thing that drives the piston/breech block rearwards and that's GAS - and plenty of it. If it ain't going back far enough then there's only TWO things stopping it. Not enough gas or excess friction in the body or return spring(s)

I'd start with some known ammo, such as ex UK military RG or RL or K and if it doesn't return the piston, piston extension/breech block assembly (we call them 'the working parts') try turning up the gas.

But as we're not familiar with your semi only gun, I can't comment further

I thought Semi-Auto's in the US. Were made to a design that fired from a CLOSED bolt, & were thus striker fired? Dimentionaly different internaly to prevent Full Auto Componants from being inserted & used?

As Peter Has stated. If ANY of the working parts are not recoiling sufficiently to ensure they going rearwards. To catch on the sear, It is ALMOST certainly lack of Gas. Turn your gas regulator round to the Next Larger port.

With the gun Field stripped, Hold the upper reciever up horizontaly, & your right hand over the reciever opening that the gas piston & Breechblock are inserted from.
raise your left arm slowly holding the right one horizontal. keep raising until the piston group move to the right/rearwards. They should move smoothly. if they dont, observe where they MAY be sticking & check & dress metal from that area IF, Required.

But, I would have thought they guy who did the reweld & remanufacture of this type of weapon. Would have had all this done before it was completed & put up for sale?.......
Just Points to check..............

Thanks for your replies guys, I have not seen the rifle except the pictures of it. It sounds to me like it is an open bolt and that's what I am worried about. All he said to me was that the bolt is not going all the way back to the sear on a few occasions and as a result is firing more than 1 round. If only this was an sa80, I know them like the back of my hand. Now if it is an open bolt what are my solutions to this problem

How come you know all about SA80/L85?
You've had TWO Armourers give you the same answer. Already we know that the working parts are being pushed far enough to the rear to feed and fire the next round in the magazine but just not quite far enough for the piston post to engage the sear. So we KNOW that the gas is working but there's not enough to give the working parts sufficient momentum to engage the sear. MORE GAS

In real life, with our service Brens, the rear of the piston extension will pretty well always beat against the internal buffer in the butt slide.

To be honest, you are working blind and so are we.................. Get the gun and you'll have it in front of you ready for when we ask the next questions. No gun, no concise answers

Who rewelded the rifle? The bolt carrier should drop right in with no friction what so ever. A common issue is binding. Their are two versions of the semi in use, hammer and striker, striker being the more common. It is not uncommon for the striker to not fit properly. You can eliminate the ammo question by using the new made Privi for test firing. Other than the Greek surplus that has all but dried up, it is the only reliable ammo. That is why most of the Bren guys have a backup 7.62x54r conversion. Cheep reliable ammo, readily available. If you are truley worried about the gun call up SMG and have it sent directly to them. They will work out the bugs and then send it to you. The are really good at what they do.

Thinking out aloud C130pilot, It can't be distortion because it's already going pretty well all the way rearwards AND it's going forwards too

you said you have seen pics
show us the pics and then you might get the answer you need
is it a home reweld or a manufacturer reweld?

From the look of the weld it is a home weld, I have seen better but I have also seen a lot worse. I will upload pictures as soon as I get home from work. I am currently looking for another kit as I would like to try to build my own, but I also like the work project guns do

Unanswered question Pengman......... How come you know about our SA80 rifles? I understand that there are only very few in the US, including one of each L86/L86 plus a parts set to convert to A2 spec for each - that we gave to the US Military a few years ago

sounds like he might be a pommy abroad

Quote:

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Originally Posted by Peter Laidler

Thinking out aloud C130pilot, It can't be distortion because it's already going pretty well all the way rearwards AND it's going forwards too

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One thing to remember though is in a US made semi, the sear catch is milled off and the carrier can short stroke. The striker adds another 1" to the rear of the carrier.

Quote:

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Originally Posted by Peter Laidler

Unanswered question Pengman......... How come you know about our SA80 rifles? I understand that there are only very few in the US, including one of each L86/L86 plus a parts set to convert to A2 spec for each - that we gave to the US Military a few years ago

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The SA80 was my service rifle when it was first introduced to my regiment back in 1989. Before that it was the good old L1A1. It would be great if we could buy the SA80 here in the U.S but it will never happen :)

---------- Post added at 11:47 PM ---------- Previous post was at 11:40 PM ----------

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Originally Posted by Mr E

sounds like he might be a pommy abroad

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You got it right. Born and raised in the U.K and moved to the U.S 11 years ago after getting married and leaving the british military. That's why I have taken to collecting British rifles.

While you're over there teaching the bible to all those wild heathen colonials Pengman, just make sure that you keep them all in line. Just remind them that if they get out of hand, I'll arrange to send a gunboat over there and take the place back off 'em! And while you're there, get them to do their spellings correctly.................... Colour, Grey and Armourers for a start!

OUCH! I would correct my poor spelling by I can't seem to find a edit thread tab. :madsmile:

Good luck with that, Peter. Remember what happened the last time y'all tried that!


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I'd bet with our current state of affairs, even the Queen doesn't want us back! Can't say I'd blame her!

Quote:

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Originally Posted by Peter Laidler

While you're over there teaching the bible to all those wild heathen colonials Pengman, just make sure that you keep them all in line. Just remind them that if they get out of hand, I'll arrange to send a gunboat over there and take the place back off 'em! And while you're there, get them to do their spellings correctly.................... Colour, Grey and Armourers for a start!

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Peter I'm afraid the only thing the royal navy could throw together is a patrol boat, the government has cut the British military to the bone. How do I post pics on this website? The guy I bought the Bren from managed to fix the issue but I do need some advice on a kit I bought but as we all know pictures speak a thousand words

Pengman. You state your seller managed to 'Fix the issue'. It would be nice to know what exactly was done for future reference of other potential owners over there.

As a lot of good advice was given freely by members on this topic. It would also be good to follow this thread to it's sucessfull conclusion.

Quote:

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Originally Posted by tankhunter

Pengman. You state your seller managed to 'Fix the issue'. It would be nice to know what exactly was done for future reference of other potential owners over there.

As a lot of good advice was given freely by members on this topic. It would also be good to follow this thread to it's sucessfull conclusion.

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All he said was the problem was a result of slam fire? Something to do with feed ramps. I think I am just going to ask for my money back on this rifle. S in the mean time I am just going to have someone assemble a kit for me and convert it into semi auto

That does sound a bit suspect to me. My interpretation of slam fire is that somthing fires the round unitensionally, dirt, a bur, seized firing pin etc. So if your first shot was on trigger press (As expected) but then it continued to fire, surely this would mean that its still short stroking as the sear hasn't cought the breech block (Or hammer/ striker, what ever it is on a US semi conversion). So it still sounds to me like he has fixed one issue but that may be masking another.

Ah........ but to this Armourer, a slam fire is just another way of describing the Sten method of firing. As in close the breech, no locking and just fire the gun!

Any ATF approved US semi-auto conversions must be to a closed bolt redesign. I'd guess it's a combination of both crap ammunition, (not enough gas), and friction from the semi-auto closed bolt design. A combination of some decent ammo, proper lubrication and turning the gas up a notch or two may well cure it.