54R Bren Issues

[Joe H]

Peter,

I'll drink to your proposal but it might take me a little while to get to your favorite pub .

Vincent,

That link to 1919a4 was great. I read about the HA Bren in Small Arms Review. Everything was wonderful. Wiselite and head-spacing OMG. When I first decided to build semi Bren I found a tutorial by "Pirate", another so-called professional builder. At that time the IO cut receivers were available so that there was one cut to weld between the locking shoulder and the barrel socket. He, probably like Wiselite, set up the weld by fitting the magazine, not setting the headspace. I couldn't believe it. I set the headspace first then checked the mag fit. If the mag didn't fit then there was something very wrong.

Wally G.

Thanks for your details of the HA build. I had read about what Len had to go through to meet ATF specs. The latest ATF approval letters are far less restrictive.

Gary,

Yes my Brens run better on .303, but they also run without any problems on 54R. If you are building your own and are willing to take care of all the small details they can be made to work with 54R both semi and FA (see post from C310 pilot about FA 54R Bren). The details being headspace, timing and the magazine. The ZB39 mag was not made for the 54R round and although it can be made to feed that doesn't mean it will work properly without modifications. There are no other reasonable magazine options.
For most people what I stated above is not the case.
My 2 cents

Djandj,

It's impossible to tell how the wood plug affects mag capacity and feeding. As far as I know this issue has never come up. I guess there are not many people with Brens in California.

Joe

[Vincent]

I know I always sing the praises of the ferocious 762x54R PKM……..

I wish you would stop doing that, Peter. Then I could stop kicking myself in the a** for passing up a really good deal on one. What was I thinking!

[Peter Laidler]

We had a tacit sort of agreed standard to restrict Bren magazines to 10 rounds dating back to the 50's or so. Only seen a couple of them including one that was in the 'shooting cupboard' of my sons old school Cadet Force. It had a steel plate brazed through the square section that extends out of the back of the magazine (the part that had the mag catch lug), positioned so that the mag platform could NOT be depressed past 10 rounds capacity.

You could insert and remove the platform for assembly and cleaning but only with a bit if jiggling with it hanging on the spring. Once past the 'blockage', it was OK. Didn't affect the free passage of the spring because the spring doesn't intrude into the rear boxy section. I took it into Warminster. Anyone interested and I'll see if it's still there and photograph it. But pretty foolproof. Used by recruits during their initial live firing so thet don't get tooooo carried away - as you are prone to do!

To be honest Vince, id'd be hard pushed to make a decisioin over a PKM and an L7/GPMG. But if it was heart rule head time, it'd be GPMG. Anything else, the PKM

[djandj]

The biggest problem is crap 54R ammo.

I've mentioned this before, and I'll say it again, the semi Bren and the full auto Bren run wonderfully on .303 and the L4 series run wonderfully in 7.62x51, so with all due respect I can't see the point in wasting range time trying to reinvent the wheel.

I know there is a fellow on another forum who's been having all sorts of trouble with a Browning 1919A4 while trying to get it to run on 54r and has been told the same thing. Stop wasting your time......

Just because something is cheap (54R ammo for example) doesn't mean its any good.

I've had several of the Historic Arms Bren's through my hands in both 303 and 308, and they all have functioned flawlessly.

Gary

With all due respect CS, my 1919a4 runs like a Swiss watch on 54R (Thanks to Troy at BarrelXchange). As for the Bren. Len BUILT IT WITH THE SPECIFIC INTENT TO SHOOT SURPLUS 54R! Why else would you convert a .303 to shoot the equally expensive (if non-surplus) 54R? Why convert it at all? Well, .303 is .70 per and drying up fast. 54R is .22 per round SHIPPED. As for being "crap" I don't see it. If you look at the steel casing that burst, they were pretty thick. That much steel will be far more tough than a comparable brass round. So? I don't know. Others have said that they have got their Brens to run on 54R. I'd like to do the same.

[Peter Laidler]

We can all see the frustration and the point you're making DJ but the simple and irrefutable FACT is that your particular gun is causing the case/cases to blow out at the point at which they are at their weakest and unsupported. At the cutout for the extractor. Your BRowning doesn't have this feature and that's why they ain't blowing out. The 7.62mm L4 barrels don't have this feature either and they don't blow out either.

Line 4 of your comment, you forget that while the steel case is tougher (? in metallurgical terms) than the equavelent brass case, the brass has several additional properties including its pliability and resiliance. THAT's why it is so good at obturating the chamber among other things of course.......

[Vincent]

obturating

That stops or plugs up; used in closing or stopping up: specifically applied to a primer for exploding the charge of powder in a cannon, and at the same time closing the vent, thus preventing the rush of gas through it in firing.

Being a layman, I had to look it up.

[djandj]

We can all see the frustration and the point you're making DJ but the simple and irrefutable FACT is that your particular gun is causing the case/cases to blow out at the point at which they are at their weakest and unsupported. At the cutout for the extractor. Your BRowning doesn't have this feature and that's why they ain't blowing out. The 7.62mm L4 barrels don't have this feature either and they don't blow out either.

Line 4 of your comment, you forget that while the steel case is tougher (? in metallurgical terms) than the equavelent brass case, the brass has several additional properties including its pliability and resiliance. THAT's why it is so good at obturating the chamber among other things of course.......

Yes Peter, quite true that the 1919 has a flatter barrel end and doesn't leave parts of the round unsupported (why in the world the Bren does that IDK). But I brought it up only b/c CS had mentioned another 54R Browning not working. Again, others seem to have managed to make the 54R thing work in a Bren so I can't see why I can't as well. Once I check the headspacing, it will be one less thing to question. After that I'm open for ideas. After all, the rifle fires 60 rounds flawlessly prior to BOOM.

[Peter Laidler]

Ah, yes, that's the point we raised a few threads ago....... 60 rounds flawlessly tells me that the support within those 60 rounds is marginal at the weak point. But every so often a case comes through that is slightly thinner or maybe there's a slight increase in pressure or..... and then a catostrophic failure occurs as we see.

I wonder if you could just borrow 2 mags worth of factory brass cased ammo and see what happens. I appreciate that this isn't quite what you should be doing but it's a good start when you're trouble shooting - if you'll excuse the pun!

My friend fires this cheap as chips steel cased 762x54 stuff in a slightly modified Vickers and it sings like a train........... It even fire-forms the front of the neck into the old .303" chamber contour without a wimper too. But at that end of the case, it's thin material and more forgiving.

[Joe H]

Djandj,

This, I know is extremely frustrating to you. As Peter mentioned earlier,if a group familiar with the Bren could get together and actually handle your rifle I think the problem could be found. You are admittedly not a gunsmith and probably not at all familiar, at least until now, with the workings of the Bren gun.

Over on the Weapons Guild (you may want to inquire over there as most of the participants are semi builders and some may have had the same issues) many of the builders have used the 54R conversion successfully and ones who posted about problems could trace them back to some sort of head-spacing issue. Csmarcher indicated that he had run a HA .308 Bren flawlessly. The barrels, I'm almost certain, HA provided were SA 7.62 x 51, not L4 barrels which are pretty much unavailable in the US. The SA barrels have the same notch as the .303 British. I have a SA 7.62 x 51 barrel and a .303 barrel converted to 8 mm Mauser. I did the same analysis that I previously posted for these two calibers by splitting the heads to be sure the solid end of the case extended past the notch for the extractor, which they did.

In addition to Peter's suggestion maybe try not using the Mag and see if any problems arise. To check to be certain your rifle can only fire with the carrier in the proper position, take a primed cartridge with the bullet and powder removed and place it in the chamber. Drop the bolt on it. Slowly withdraw the carrier/bolt until the carrier is on the verge of unlocking the bolt. Now ease the bolt toward open and try to hold the carrier in the rear position, just about to unlock, Position B in my previous illustration. Pull the trigger. If it fires the primer something may be preventing the carrier from fully locking the bolt. If it doesn't fire try again with the carrier half way to locked position. You may have to remove the return spring for the test. Of course the striker spring has to stay in place. If I had your gun I'd check headspace first then do this test. If it headspaces ok and fails this test I'd be trying to find out why carrier is not returning consistently to fully locked position.

IMO either the headspace is too loose for the 54R or for whatever reason it is intermittently able to fire out of battery or at least not fully locked up. Drag on the return cycle, possibly a mag issue. Other than that I'm out of suggestions

Joe

[csmarcher]

Csmarcher indicated that he had run a HA .308 Bren flawlessly. The barrels, I'm almost certain, HA provided were SA 7.62 x 51, not L4 barrels which are pretty much unavailable in the US.

Joe

I'm actually a very lucky chap and have TWO L4 barrels for my L4A3 that Len built. I actually managed to obtain a "Bren Conversion Kit" back in the late 80's from IMA which came with an L4 Barrel, 7.62mm Breech Block, L4 Mag catch and ejector housing and instructions....

From that Len was able to build a true L4 series gun for me on an Inglis Mk II reciever.
I found the 2nd barrel on Gunbroker in a mixed lot of Bren parts that the seller had no idea what he had his hands on.....

I'll post a video of it on the range later on.

G