Bren bbl lock-up help

**stimpsonjcat** · December 12, 2011, 10:44

OK, dug thru my spare Bren bbls and found a real sewer pipe to sacrifice to rechamber for 7.62x54R. That all went well.

Problem is the bbl has been peened, intentionally it looks like to me, on the interrupted threads that the bbl locking ring locks onto. The bbl slides into the receiver well enough, but then the locking ring cannot rotate to the fully closed and locked position.

I *believe* that the locking ring 'pulls' the bbl into the receiver when rotated, and so I suspect I just need to dye-chem and file the side of the threads towards the muzzle until it closes. I was just looking for confirmation this is the appropriate solution.

Gonna be a pain figuring out which of the 12 thread pieces needs filing to get happy. I feel lots of file-check-mark coming on...better buy some new sharpies!

My fault I guess...should have checked fit in the receiver before chambering.

If this is naughty behavior for some reason, please let me know. My main concern would be if this causes uneven forces on the receiver. It seems like this could happen pretty easily if I do not get all the threads exactly right. If so then I may just chamber another bbl.

tac-40 · December 12, 2011, 11:04

You stated the threads on the barrel were peened. If it is that obvious, then you should already be able to see where you would need to file the high spots.

Since those are square cut threads, I would say if just the outer portion is damaged, then you would be safe in filing them down. The threads near the root would pick up the slack and still keep everything in alignment. If you have to go too deep, you might have other problems besides the damaged threads.

**stimpsonjcat** · December 12, 2011, 11:14

Excellent point Tac...I will go ahead and get them back to correct profile and see if that solves it.

**stimpsonjcat** · December 19, 2011, 14:53

A little sharpie and file-work and all is well.

Bren is now functional in 54r.

Now to make some hybrid mags to solve the feed issues with 54r in Bren mags.

**L1A1Johnno** · December 20, 2011, 00:21

Hope to have my semi bren running in a few weeks and was also going to go the 54R route as well
Did you ream it yourself or use a gunsmith to do it?
Any pointers to make the job easier?
How did you control the headspace?
Are you going to modify the 303 mags for good feeding? If so how?

Really interesting firearm and definately underrated by most

Any photos??

best of luck with the project

Cheers
Johhno

**stimpsonjcat** · December 20, 2011, 09:20

Quote:

Originally posted by L1AIJohnno
Hope to have my semi bren running in a few weeks and was also going to go the 54R route as well
Did you ream it yourself or use a gunsmith to do it?

I did it myself.

Quote:

Any pointers to make the job easier?
How did you control the headspace?

I chucked the muzzle end up in my lathe, centered the outboard in my steady, put the reamer in the tailstock and cut until the round just barely seated against the bbl face. This just happened to be where the reamer barely touched the bbl face. Checked headspace with just the bolt/bbl in the receiver and it was fine.

Quote:

Are you going to modify the 303 mags for good feeding? If so how?

I have purchased 2 Finnish 20 round mags that were made for a lahti in 54r. I plan to cut apart 2 bren mags just up from the feed lip/lock up area and cut the lahti mag the same and then weld the lahti body on the bren feed section. I think this will help with the feeding of the rounds as my understanding of the problem is that the difference in curvature causes the problems. We'll see, they may not mate up well at all.

Quote:

Really interesting firearm and definately underrated by most

Any photos??

best of luck with the project

Cheers
Johhno

**L1A1Johnno** · December 20, 2011, 17:03

Hey Simpson
No need to go to that Mag extreme
go to MG 34 website and they have ZB-39 mags in 8 x 56R ready to rock n roll for 20 bucks each. Fit straight in and feed just fine.

Many thanks for the Bren Info mucho apreciardo etc

What did you do for a receiver welding Jig?
Had one but it was marginal in my thoughts so going to do it again right this time and make a few mods to make it bulletproof - ha

Please keep the pictures coming love them all

Merry Christmas to all

Cheers

Johnno

**stimpsonjcat** · December 20, 2011, 19:42

Shiny!

Uhhhhh...what website?

That means moving on to another project!

I have detailed pics of my jig with dimensions on it...shoot me an email addy and I will send them.

**L1A1Johnno** · December 20, 2011, 23:02

www.mg34.com

click on ZB39 and voila - mags galore

OK will send you email, many thanks for the help getting the monster back together

Cheers

Johnno

December 12, 2011, 10:44	#1
stimpsonjcat Windoze free since 1-2010 Silver Contributor FALaholic #: 470 Join Date: Jul 2000 Location: Dawsonville, GA Posts: 4,200	Bren bbl lock-up help OK, dug thru my spare Bren bbls and found a real sewer pipe to sacrifice to rechamber for 7.62x54R. That all went well. Problem is the bbl has been peened, intentionally it looks like to me, on the interrupted threads that the bbl locking ring locks onto. The bbl slides into the receiver well enough, but then the locking ring cannot rotate to the fully closed and locked position. I believe that the locking ring 'pulls' the bbl into the receiver when rotated, and so I suspect I just need to dye-chem and file the side of the threads towards the muzzle until it closes. I was just looking for confirmation this is the appropriate solution. Gonna be a pain figuring out which of the 12 thread pieces needs filing to get happy. I feel lots of file-check-mark coming on...better buy some new sharpies! My fault I guess...should have checked fit in the receiver before chambering. If this is naughty behavior for some reason, please let me know. My main concern would be if this causes uneven forces on the receiver. It seems like this could happen pretty easily if I do not get all the threads exactly right. If so then I may just chamber another bbl. __________________ peace! Happiness=UPS+ORMD "Your 8mm FAL is like a deuce coup with a Ferrari pancake 12 under the hood and a Jaguar rear end. It just kinda transcends cool into fantasy."- USMC 0341 "The stimpgewehr is the reason Waldo is hiding."- Kotengu Cause I can still hear his voice when I put it to my shoulder, "A guns like a woman son, it's all how you hold her."

December 12, 2011, 11:04	#2
tac-40 Moderator Armed Curmudgeon FALaholic #: 12090 Join Date: Oct 2003 Location: SC-Low Country Posts: 4,526	You stated the threads on the barrel were peened. If it is that obvious, then you should already be able to see where you would need to file the high spots. Since those are square cut threads, I would say if just the outer portion is damaged, then you would be safe in filing them down. The threads near the root would pick up the slack and still keep everything in alignment. If you have to go too deep, you might have other problems besides the damaged threads. __________________ Only 2 defining forces have ever offered to die for you.....Jesus Christ and the American Soldier. One died for your soul, the other for your freedom. Lt. Col. Grant L. Rosensteel, Jr. USAF ______________________________ If you do in fact have a problem, you have the rest of your life to solve it. How long your life lasts only depends on how well you solve it.

December 12, 2011, 11:14	#3
stimpsonjcat Windoze free since 1-2010 Silver Contributor FALaholic #: 470 Join Date: Jul 2000 Location: Dawsonville, GA Posts: 4,200	Excellent point Tac...I will go ahead and get them back to correct profile and see if that solves it. __________________ peace! Happiness=UPS+ORMD "Your 8mm FAL is like a deuce coup with a Ferrari pancake 12 under the hood and a Jaguar rear end. It just kinda transcends cool into fantasy."- USMC 0341 "The stimpgewehr is the reason Waldo is hiding."- Kotengu Cause I can still hear his voice when I put it to my shoulder, "A guns like a woman son, it's all how you hold her."

December 19, 2011, 14:53	#4
stimpsonjcat Windoze free since 1-2010 Silver Contributor FALaholic #: 470 Join Date: Jul 2000 Location: Dawsonville, GA Posts: 4,200	A little sharpie and file-work and all is well. Bren is now functional in 54r. Now to make some hybrid mags to solve the feed issues with 54r in Bren mags. __________________ peace! Happiness=UPS+ORMD "Your 8mm FAL is like a deuce coup with a Ferrari pancake 12 under the hood and a Jaguar rear end. It just kinda transcends cool into fantasy."- USMC 0341 "The stimpgewehr is the reason Waldo is hiding."- Kotengu Cause I can still hear his voice when I put it to my shoulder, "A guns like a woman son, it's all how you hold her."

December 20, 2011, 00:21	#5
L1A1Johnno Member Silver Contributor FALaholic #: 15133 Join Date: Aug 2004 Location: Gun Friendly Nevada Posts: 326	calibre change Hope to have my semi bren running in a few weeks and was also going to go the 54R route as well Did you ream it yourself or use a gunsmith to do it? Any pointers to make the job easier? How did you control the headspace? Are you going to modify the 303 mags for good feeding? If so how? Really interesting firearm and definately underrated by most Any photos?? best of luck with the project Cheers Johhno

December 20, 2011, 17:03	#7
L1A1Johnno Member Silver Contributor FALaholic #: 15133 Join Date: Aug 2004 Location: Gun Friendly Nevada Posts: 326	so cool - thanks Hey Simpson No need to go to that Mag extreme go to MG 34 website and they have ZB-39 mags in 8 x 56R ready to rock n roll for 20 bucks each. Fit straight in and feed just fine. Many thanks for the Bren Info mucho apreciardo etc What did you do for a receiver welding Jig? Had one but it was marginal in my thoughts so going to do it again right this time and make a few mods to make it bulletproof - ha Please keep the pictures coming love them all Merry Christmas to all Cheers Johnno

December 20, 2011, 19:42	#8
stimpsonjcat Windoze free since 1-2010 Silver Contributor FALaholic #: 470 Join Date: Jul 2000 Location: Dawsonville, GA Posts: 4,200	Shiny! Uhhhhh...what website? That means moving on to another project! I have detailed pics of my jig with dimensions on it...shoot me an email addy and I will send them. __________________ peace! Happiness=UPS+ORMD "Your 8mm FAL is like a deuce coup with a Ferrari pancake 12 under the hood and a Jaguar rear end. It just kinda transcends cool into fantasy."- USMC 0341 "The stimpgewehr is the reason Waldo is hiding."- Kotengu Cause I can still hear his voice when I put it to my shoulder, "A guns like a woman son, it's all how you hold her."

December 20, 2011, 23:02	#9
L1A1Johnno Member Silver Contributor FALaholic #: 15133 Join Date: Aug 2004 Location: Gun Friendly Nevada Posts: 326	MG 34 www.mg34.com click on ZB39 and voila - mags galore OK will send you email, many thanks for the help getting the monster back together Cheers Johnno

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