54R Bren Issues

[Joe H]

I've been watching this since the beginning and just about can't stand the amount of fiddling this thing has needed. The whole problem is a gun needs to be headspaced as a unit when completed and not piecemeal. I get the impression the barrel and bolt are done remotely and not to the very gun they're installed in. If you start with a new barrel, you can do it to spec and end this misery. Then you should be able to shoot whatever ammo comes to hand...

AMEN --- Gunsmithing 101 , exactly why new commercial barrels come short chambered ---

Joe

[djandj]

I agree with BAR (thread 265). That way you can ream to EXACTLY what you want/need it to be.

The strange part about this saga is that it did work and function correctly using brass cased ammo! I realise that that isn't the point but none the less, it's a fact!

Yep. Which makes it all the more confusing since if it were ONLY a head spacing issue, the brass shouldn't have fixed the problem. But it did. Furthermore, changing barrels to Vince's barrel also didn't change the HS either, yet so far no gas explosions. So.... maybe just the barrel cut wrong and NOT a HS issue?

[TactAdv]

Have you thought to measure the rim thickness of the several different ammunition choices you have used??

I've found considerable differences in "identical" calibers in the rim thickness over the years in various cartridges.

A couple thousandths of differing rims would effect headspace.....

Just one more data point to document/investigate.

-TomH

[Joe H]

Yep. Which makes it all the more confusing since if it were ONLY a head spacing issue, the brass shouldn't have fixed the problem. But it did. Furthermore, changing barrels to Vince's barrel also didn't change the HS either, yet so far no gas explosions. So.... maybe just the barrel cut wrong and NOT a HS issue?

Djandj,

You still don't understand HS. When you changed barrels you decreased the HS by the depth of the recess that was cut by the reamer in your previous barrel. It had nothing to do with the depth of the notch. The notch depth below the rim is the same no matter how deep the recess is. The cutting ears on the reamer "that shouldn't be there" cut the 54r rim diameter and can be used for small adjustments for fitting a new barrel that needs a little more HS.

You did have different problems with the brass cases. The case solid head may be longer than the steel like the .303, you don't know.

The big number you haven't posted is with the bolt on the stops, not on the case head as you posted, what is the distance between the case head & bolt face. It can't be checked with a feeler gage. You don't know "Sh--T" about the headspace on your Bren until the bolt face can rest on the case head or a proper HS gage.

You may have just decreased HS enough to eliminate blowouts. I didn't say correct HS.

Read browningautorifle's comment above.

Get a gunsmith, who knows what he is looking at, evaluate your rifle.

Joe

[djandj]

Djandj,

You still don't understand HS. When you changed barrels you decreased the HS by the depth of the recess that was cut by the reamer in your previous barrel. It had nothing to do with the depth of the notch. The notch depth below the rim is the same no matter how deep the recess is. The cutting ears on the reamer "that shouldn't be there" cut the 54r rim diameter and can be used for small adjustments for fitting a new barrel that needs a little more HS.

You did have different problems with the brass cases. The case solid head may be longer than the steel like the .303, you don't know.

The big number you haven't posted is with the bolt on the stops, not on the case head as you posted, what is the distance between the case head & bolt face. It can't be checked with a feeler gage. You don't know "Sh--T" about the headspace on your Bren until the bolt face can rest on the case head or a proper HS gage.

You may have just decreased HS enough to eliminate blowouts. I didn't say correct HS.

Read browningautorifle's comment above.

Get a gunsmith, who knows what he is looking at, evaluate your rifle.

Joe

Joe - I'm with you. I'm doing what I can with what I have. If there is a head spacing gauge (as opposed to the feeler gauge) I can get it and see, but we pretty well know the barrel that was sent with the rifle is incorrect (I don't need a gauge to tell me that). We also know that so far Vince's barrel seems to be working. That's the best I can do w/o a micrometer. (or head spacing gauge). If anyone has one for 54r and is willing to send it to me, I will use it and report back.

The problem the Historic Arms barrel had with the brass has resolved. (probably burrs or something in the chamber left over from the blowouts with the steel). After 60 rounds of the brass, it no longer has the extraction issue with the brass. For what that is worth as I don't want to shoot brass with this rifle.

As for the "professional gunsmith" For the most part, these guns don't seem to be built by "professional gunsmiths". From what I have seen and heard many/most are garage builders moonlighting with building these things or very small shops that have very limited capacity. I have spoken with two of them so far. NONE have any availability in the foreseeable future to do the work on the gun. Probably b/c this is not their "day job"

I admit that "trial and error" are not the most direct method... but it may eventually get me there (and make for interesting web board fodder)

Thanks for all the help guys. Lord knows I need it (and very much appreciate it)

I will continue to test Vince's barrel with the steel. If it makes the next range trip with 200 rounds without incident, I will simply arrange to buy that barrel, get it parkerized to match the gun and shoot the bloody thing in piece without ever knowing what the head spacing is.

---------- Post added at 08:15 PM ---------- Previous post was at 08:13 PM ----------

Have you thought to measure the rim thickness of the several different ammunition choices you have used??

I've found considerable differences in "identical" calibers in the rim thickness over the years in various cartridges.

A couple thousandths of differing rims would effect headspace.....

Just one more data point to document/investigate.

-TomH

Thanks, yes, Tom I have. Surprisingly the Russian surplus I have is remarkably consistent at exactly .063 (or whatever Peter mentioned in the earlier post)

[Joe H]

Joe - I'm with you. I'm doing what I can with what I have. If there is a head spacing gauge (as opposed to the feeler gauge) I can get it and see, but we pretty well know the barrel that was sent with the rifle is incorrect (I don't need a gauge to tell me that). We also know that so far Vince's barrel seems to be working. That's the best I can do w/o a micrometer. (or head spacing gauge). If anyone has one for 54r and is willing to send it to me, I will use it and report back.

Djandj,

"can't use a feeler gage" The special gage is your finger. With the bolt pushed against the stops if you can move the case with your finger you have a problem. With the bolt face on the case head the stops should clear the bolt by approx. .005"

Joe

[djandj]

Djandj,

"can't use a feeler gage" The special gage is your finger. With the bolt pushed against the stops if you can move the case with your finger you have a problem. With the bolt face on the case head the stops should clear the bolt by approx. .005"

Joe

That's Funny! Why didn't you TELL me about the finger gauge! I have ten of those. LOL Anyway, as I have tried to photograph. The bolt appears to rest directly upon the stops - not the shell casing. Whether there is a round in the chamber or not it makes no difference (or so it seems) there is NO movement of the bolt in either case. I cannot see ANY separation between the stops and the bolt face. I can look again, but without an actual measuring device it's just best guess and Kentucky windage (especially when you are talking thousands of an inch).

[ActionYobbo]

get some white board marker and coat the shoulders of the bolt with it and let it dry. with a dummy in the chamber put the bolt in the receiver (no extractor or firing pin) and try to push the bolt hard against the dummy round. take the bolt out and the marker will be gone from where it contacted the shoulders.

[Peter Laidler]

Surely chaps........... if the gun is now functioning and firing OK now, with brass and steel, then maybe on the basis that if it ain't broke, then don't fix it and it's time to leave the bloody thing alone! Sure, there might be a few niggling problems here and there but like your trusty old Norton motorcycle, it's running well and is doing all you ask of it - so do you worry that there's a drip of oil on the garage floor or the typically Lucas brake light switch contacts needs cleaning every week?

Yep...., that's from a Norton owner! I expect there are some Land Rover owners who might feel the same...... and Triumph car and bike owners too!

[djandj]

OK gang. The final update. With now 260 rounds of steel cased ammo fired with Vincent's (properly reamed barrel) and having suffered NO malfunctions, I have to say, the answer was.... improperly reamed barrel! No other changes were made to the rifle.

So.... now the only question is.... where can I get a properly reamed barrel that is parkerized (to match the gun) and if possible, has the slots on the bottom of the barrel as seen in the pic below.