54R Bren Issues

[Joe H]

strip the gun turn the receiver upside down and insert just the carrier. it should move freely under its own weight when you tilt the receiver up and down 30 degrees.
now do the same test with the carrier and the bolt. its should lock and unlock just by tilting. the carrier should travel forward until the piston post stops it.
now with a stripped bolt and a dummy round do the test again. with your finger hold the carrier to the rear. insert the dummy into the chamber. tilt the receiver down at 30 degrees and release the carrier. parts should go forward and achieve lock up. unlock should be achieved by tilting up 30 degrees (a slight bump might be needed)
put 2 layers of masking tape on the dummy round and repeat

if you pass all these steps the gun is good. if one of these steps fails then you have a problem

Mr E. ,

Exactly how I check a welded up semi except I add shims to the dummy. You can't use any springs as they will mask any problems.


Joe

[djandj]

Attachment 62903

Want to try this one?

Thank you Vince. PM sent. Can't thank you enough.

[djandj]

Djandj,

Exactly what are you trying to achieve? The thread started out to try to find out why you couldn't shoot 54r steel cased light ball in your semi Bren. You were concerned about the cost of brass cased ammo. The Yugo heavy ball, from what I can tell, is still about 50% for large quantities at best more than the steel cased 54r. Is the Yugo ammo corrosive?

You rightly noted that many other semi Bren users are shooting 54r steel cased light ball in their Brens without the problems you are experiencing. There is something wrong with the way your Bren is functioning.

You are now trying 54r brass cased heavy ball and the cases are sticking. Just as Peter suggested some oil may solve this particular problem. The Bren, its predecessors, the ZB guns, or caliber variations were never designed to require oiled cases to allow proper function. Any military firearm that did is just an obscure footnote to history.

IMO you may get your Bren to function marginally with the brass cased heavy ball but you haven't solved the problem with your gun nor have you solved your initial question in this thread.

Joe

You are absolutely correct Joe. I'm doing what I can. I sent it back to the builder after years of problems with 80 rounds of steel. He sends it back claiming to have fired all 80 rounds with no problems. I can't imagine that as it blows up after as few as two rounds. The builder tells me it's bad ammo (?) The same stuff I sent him to tune the gun to. So.... then after talking to many of you here, it was again suggested - try the brass. So.... I tried the brass, and the problem changed. Same cause? No one knows. So I'm trying to collect data on it. Not sure what more I can do at this point.

To answer the question: I'm just trying to get the rifle to shoot RELIABLY with ANY ammo at this point.

[Vincent]

Thank you Vince. PM sent. Can't thank you enough.

Some of the members here have been extremely generous and helpful to me. I will never be able to thank them enough. The best I can do is to try to follow their example when I can.

The locking shoulder screw is buggered up. You will have to reuse the one you have. It will be staked in and very had to get out. Maybe Peter or some of the other guys with experience can tell you how to get the screw out without damaging it.

Locking shoulder screws are very hard to find.

[ActionYobbo]

Some of the members here have been extremely generous and helpful to me. I will never be able to thank them enough. The best I can do is to try to follow their example when I can.

The locking shoulder screw is buggered up. You will have to reuse the one you have. It will be staked in and very had to get out. Maybe Peter or some of the other guys with experience can tell you how to get the screw out without damaging it.

Locking shoulder screws are very hard to find.

good job there Vincent

to get the screw out I drill away the area that has been staked. you will need a long drill to reach in there. just remove whats to the outside of the circle. the screw is not in very tight and once drilled will turn easily. the screw can be used again and when you are sure that you dont need to remove it again you can stake it on the remaining area of the screw.

if you bugger it up I have a NOS screw that I can send you

[djandj]

good job there Vincent

to get the screw out I drill away the area that has been staked. you will need a long drill to reach in there. just remove whats to the outside of the circle. the screw is not in very tight and once drilled will turn easily. the screw can be used again and when you are sure that you dont need to remove it again you can stake it on the remaining area of the screw.

if you bugger it up I have a NOS screw that I can send you

No worries Vince. I already pulled my shoulder screw and it came right out with no problem. Apparently it wasn't stacked too deeply or whatever. I can just screw it right back in with the new shoulder.

[tankhunter]

An Impact Driver, Used Correctly. Will also remove a L/Shoulder screw with ease!

[Joe H]

The locking shoulder screw is buggered up. You will have to reuse the one you have. It will be staked in and very had to get out. Maybe Peter or some of the other guys with experience can tell you how to get the screw out without damaging it.

Thanks tankhunter for the impact idea. I've used an air powered micro pencil grinder. These days you can get an import for $30 very handy for many jobs.

Joe

---------- Post added at 07:11 AM ---------- Previous post was at 07:05 AM ----------

You are absolutely correct Joe. I'm doing what I can. I sent it back to the builder after years of problems with 80 rounds of steel. He sends it back claiming to have fired all 80 rounds with no problems.

Djandj,

Just a thought, but did the builder use your 10 rd California mag for his test or his own mag?

Joe

[Vincent]

Attachment 62938

Here’s another thing you might check. Look at the return spring rod and the inside of the striker spring.

I am not seeing anything in this design to prevent the striker spring from bending and contacting the return spring rod when the striker spring is compressed.

If the striker spring is touching the return spring rod and creating friction there will be less force available to push the carrier forward and lock the bolt.

Are the return springs in your gun Standard Bren springs or a stronger?

[djandj]

Attachment 62938

Here’s another thing you might check. Look at the return spring rod and the inside of the striker spring.

I am not seeing anything in this design to prevent the striker spring from bending and contacting the return spring rod when the striker spring is compressed.

If the striker spring is touching the return spring rod and creating friction there will be less force available to push the carrier forward and lock the bolt.

Are the return springs in your gun Standard Bren springs or a stronger?

Thanks Vince. If I remember correctly, Len said he used 8MM springs. Not sure if it matters but....

---------- Post added at 05:13 PM ---------- Previous post was at 05:10 PM ----------

OK UPDATE: I went to the range with 100 rounds of brass cased Yugo heavy ball. 40 unlubed and 60 lubed with Dillion case lube. I started with the first unlubed 40 on the second to lowest gas setting. All fired perfectly!.
Then shot all 60 lubed cases with no problems as well. I have no explanation as to why this is. But I suppose it is a pleasant result.

Since Vince was kind enough to stone and send over a shorter locking shoulder piece, I will get that and try it out again with both brass and steel and report back. At least I know I can shoot brass cased Yugo through it.

Thanks again all.