Semi Auto Bren extract problem

Hi all,

Please forgive me if this is an old thread or have already been answer. I got a semi auto Bren from a guy on Gun Broker in April 2016 with 2 barrels, one in original .303 and the other in 7.62X54r, he stated that he built it using Len Savage semi auto kit. Last Sunday I brought it out the first time and get nothing but trouble. First I try the .303 barrel and the breech lock (bolt) only move partially (about half way back) after the round goes off then put the empty case back to the chamber, I have to remove the barrel to get it out because the carrier stuck and I cannot pull it back. I adjust the gas regulator to max (number 4) and get the same problem, even with the 7.62X54r barrel. Have anyone get the same problem that I have? mine come with 2 springs, the small long one (recoil spring?) in the butt stock and the short fat one connect to the striker. I check the gun and nothing seem to bind, the bolt, carrier and striker slide in smoothly. When I try to load a single round and not fire it, then pull the carrier back manually the round extract fine. Any help would be appreciated.

Thank you all in advance

Loc Chau

Have you called Len Savage? His semi conversion is different from the others.

I think some of his Historic Arms Brens had the gas ports drilled out to get them to work. I would check with him and ask if that’s what it needs.

There are about a zillion pages of talk and info about the woes of semi auto Brens. I suggest that you get yourself a LARGE glass of good scotch and start bringing the pages up - and inwardly digest both the info therein - and the scotch!

Thank you both Vincent and Peter Laidler sir, will do as you both advised. The reason that I did not call Mr. Savage is that I have called him last April when I get the gun for a spare firing pin and he told me that it has been years since his last Bren builds and that he wasn’t working on Bren gun since. My problem seem like it gas and/or spring related and I have read somewhere on this site there is thread that someone posted that the barrel, gas regulator and gas block need to be drill out and he also have all of the holes dimension. I will give that a try and will post result as soon as I get chance to go to the range. Thank you both for your reply and you both have a good day.

Best Regards

Loc Chau

I have one of Len's builds in 7.62mm NATO. When I had my gas block set to 1 I was getting problems with ejection of the spent shell. When I turned up to 2 everything was fine. Have you cleaned all the gas system out thoroughly? Is the striker spring pushed all the way back into the buttstock socket and does the coil look uniform all the way along? Mine was crushed in a few places causing light strikes but maybe that could be stopping the bolt coming all the way back if it is compressing unevenly.

:thup: Please keep us posted Loc Chau.

can you post some pics of your parts. you say the guy built it from parts he got from len savage. so from that I assume its not marked historic arms. depending on how the welding was done I am going to say that the striker is not fitted properly and is working as a brake stopping the carrier at the first weld join

Thank you all. Scoobsean, both of my barrels regulators set to max no4. Striker spring insert all the way into socket and look good. Mr E, you are correct. The receiver have BREN MK II mark and nothing else, the top behind the rear sight has serial number. I have uploaded some pictures of the parts hopefully someone can see fault if any, and the entire weld seams are very good inside and out. As I stated earlier, if I load a single sound to the chamber then pull the bolt and carrier manually back the round will eject and this does not take lot of effort to pull the carrier back manually. Also, the action is very smooth until the end as you can feel the striker spring compress. I used Wolf Performance Military Classic 174Gr FMJ .303 and Russian surplus FMJ light ball 7.62X54r. I still try to figure the best way to open the regulator holes since they are not straight through.

Quote:

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Originally Posted by locchau

Thank you all. Scoobsean, both of my barrels regulators set to max no4. Striker spring insert all the way into socket and look good. Mr E, you are correct. The receiver have BREN MK II mark and nothing else, the top behind the rear sight has serial number. I have uploaded some pictures of the parts hopefully someone can see fault if any, and the entire weld seams are very good inside and out. As I stated earlier, if I load a single sound to the chamber then pull the bolt and carrier manually back the round will eject and this does not take lot of effort to pull the carrier back manually. Also, the action is very smooth until the end as you can feel the striker spring compress. I used Wolf Performance Military Classic 174Gr FMJ .303 and Russian surplus FMJ light ball 7.62X54r. I still try to figure the best way to open the regulator holes since they are not straight through.

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Have you looked down the gas tube where the piston goes. The fact that it does it with both barrels seems to suggest something that is on the body of the gun. Maybe a blockage?
Can you post a picture of the bolt face and extractor too?

Some more food for thought... Thanks for the detailed pictures. Your source said he built the gun... not Len Savage. The design is the Historic Arms design... but there are details pictured that point to it being a home built. Whether it has ever functioned reliably is undetermined. Did the seller say what components were purchased from Historic arms? If the striker spring came from another source then it may be too strong and is prematurely retarding the rearward movement of the internals. The recoil spring shown appears to be the standard outer spring or a Mk I. You have an original gas piston shown installed on the bolt carrier (not the usual US made version found on a Historic Arms produced gun - to comply with 922r US made parts count) so it could be that you're also bleeding off gas from a worn piston, or oversized gas cylinder bore or some combination of both. As you indicated... In many cases the gas port in the barrel and the largest orifice in the gas block were drilled over sized by Len to allow for more gas to drive the system. Adjust these holes conservatively and in small increments as once removed... metal is hard to put back. If Len did not build this gun I can understand why he is hesitant to try and address its current malfunctions- too many unknowns in its construction. Hope it works out for you.

Quote:

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Originally Posted by WallyG.

If the striker spring came from another source then it may be too strong and is prematurely retarding the rearward movement of the internals. The recoil spring shown appears to be the standard outer spring or a Mk I. YAs you indicated... In many cases the gas port in the barrel and the largest orifice in the gas block were drilled over sized by Len to allow for more gas to drive the system. Adjust these holes conservatively and in small increments as once removed... metal is hard to put back. If Len did not build this gun I can understand why he is hesitant to try and address its current malfunctions- too many unknowns in its construction. Hope it works out for you.

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Can't add much to what Wally said. Could be a combination of a too strong striker spring and a weak return spring. The MK I return spring? in the pic was replaced by a double spring in all Mks. I had an old MkI spring and had to replace it with the double spring. The semi's can be made to run on gas setting 3 or 4 but for best reliability the holes should be opened up since you are compressing an additional spring in the semi set up.

Looking back at your pics. the first thing i would question is the striker spring setup. Looks way too stiff. I've built semis with a striker spring in that location but it was much smaller and just slipped over the return rod , went back in the return rod hole and cocked the striker on the bolt return.

Thread on resizing gas system:

https://www.milsurps.com/showthread.php?t=45105

Good Luck

Joe

Scoobsean, I will take the pictures you asked this afternoon when I get off from work and maybe some pictures inside too if I can. WallyG, all I’ve got from the seller is that he bought the semi kit from Historic Arms. I suppose that the kit contain all semi parts including striker, striker spring and semi trigger parts. I should have asked the seller if the gun’s working before buy it, but I didn’t. I have send the seller an email of how he build the gun and if he had drill the barrel or gas regulator but he did not reply, maybe I can get an US piston and try to replace the original one before trying to drill the regulator ports. I read some old thread and someone (I think Joe H if I get it right) have try to drill the barrel and regulator, below is his information

The Historic Arms (Len Savage's conversions) SA Brens have had the barrel and regulator ports opened hugely. Even with no receiver binding, they have little power reserve. Don't have the sizes in my head, but it ought not to be too hard to source the numbers

I checked the gas hole sizes. The Bren barrel hole is .150" as is the #4 port on the regulator. The exit nozzle on the gas block is .161". The regulator #1 port is .101", #2 - .116", #3 - .136", #4 - .150"

Since I'm using #3 and mostly #4 I'm going try to redo the gas system to work on #2. Hopefully that will give me some measure of reserve.
Below are all Number (wire gage) size drills.
Trial Modified Gas System for semi-auto
Barrel hole - .185" #13
Gas block exit - .196" #9
Regulator #1 - .1285" #30
Regulator #2 - .147" #26
Regulator #3 - .1695" #18
Regulator #4 - .185" #13
Barrel hole & gas block exit were no problem with HSS drill bits. The regulator was a different story so I annealed it and am sure it now can be drilled with normal tooling. I'm hesitant to use carbide since it chips easily and I'd have to buy all the drill sizes. I've got an old spare barrel & regulator to experiment with. I doubt it will be necessary to re-harden the regulator after it has been drilled for semi operation.

Note. Mr. Joe H, I Apology not seeing your thread until after I posted. Do you have any luck with drilling the barrel and regulator holes as you mention on some of the old thread? I will start with a new striker spring, double recoil spring and will look at the old thread that you recommended. As I mention, the seller did not get back to me and as WallyG said Mr. savage reluctant to have anything to do with and I don't blame him. Thank you all for the helpful information that you all provided, hope I can get this gun to work and I really that I have learn so much from all of you in the last couple days.

locchau,

The link I posted will give you the specs for the piston head diameter and my drilling trial for the gas system.

Checking the head dia. of the piston will give you an indication if that is part of your problem. I did successfully drill out a regulator to the sizes I posted. The barrel hole and exit hole can easily be done with a hand electric drill. The regulator is another story. It is hardened and has to be annealed (heat to 1600 deg F and slow cool) before it can be drilled with HSS tooling. Each port on the regulator is 2 cross-drilled holes. I did the drilling in a mill and it was very tedious as each hole had to be lined up then drilled, 2 setups per port.

I'd be looking at the springs and any indication of binding before I did anything to the gas system. With no round in the chamber pull the cocking handle back slowly, see if you notice a change in force particularly at the location where the case is just fully out of the chamber.

I've never handled or seen a Historic Arms Bren so I really can't comment on how they should be set up.

Joe

Quote:

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Originally Posted by Joe H

locchau,

The link I posted will give you the specs for the piston head diameter and my drilling trial for the gas system.

Checking the head dia. of the piston will give you an indication if that is part of your problem. I did successfully drill out a regulator to the sizes I posted. The barrel hole and exit hole can easily be done with a hand electric drill. The regulator is another story. It is hardened and has to be annealed (heat to 1600 deg F and slow cool) before it can be drilled with HSS tooling. Each port on the regulator is 2 cross-drilled holes. I did the drilling in a mill and it was very tedious as each hole had to be lined up then drilled, 2 setups per port.

I'd be looking at the springs and any indication of binding before I did anything to the gas system. With no round in the chamber pull the cocking handle back slowly, see if you notice a change in force particularly at the location where the case is just fully out of the chamber.

I've never handled or seen a Historic Arms Bren so I really can't comment on how they should be set up.

Joe

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I bought 3 striker springs from Len Savage when I realized the one I had was ruined. I will measure one of my spares and post that info and a photo

locchau,

Here are the original Bren sizes for the gas system. You can quickly check the barrel hole, exit port & #4 port to see if the previous owner had drilled it out to Historic Arms spec.

The Bren barrel hole is .150" as is the #4 port on the regulator. The exit nozzle on the gas block is .161". The regulator #1 port is .101", #2 - .116", #3 - .136", #4 - .150"

Possibly the Historic Arms Bren required the gas port to be drilled out to function properly.

Joe

The Historic Arms Bren djandj has in 54R has the standard gas regulator and barrel port.

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Loc Chau, Do you used the same breech block (bolt) for .303 and 54R?

how much force is needed to pull the charging handle to the rear?
mine is no harder than the FAL

Again, thank you all for all of the help and in formations that you all provided. I just took some pictures of the bolt face and inside of the receiver. I have removed the striker spring and with just the recoil spring, it is so much easy to pull the bolt carrier back. It is much stiffer with the striker spring in place. I also find that there is very little biding on the carrier with the semi auto welded to prevent original carrier to be install on the side of the receiver, I am dremeling it to smooth it out (stoning and polish) a little at a time. I have made a short video of the binding, hope it come out ok. Joe, I’ll check the barrel and exit port from work tomorrow. The machine shop guy is cool and he also on gun stuffs. Vincent, Yes I use the same breech lock for both and its look like the bolt is enlarge for 7.62X54r. Mr. E it is much stiffer than an FAL with the striker spring installed. I ordered the MK2 recoil spring from BRP Corp Store today, will get it sometime next week. Where can I find a lighter recoil spring? Is it ok to use different striker spring since my striker hole is for the large diameter spring. I took Mr Laidler advice, but instead of Scotch that he recommended I used Heineken and Cognac and they are kicking my a** now. I’ll be dreaming and hope this gun will be working soon, you all have a good night.

PS. The regulators are different on two barrel, my guess is one for MK2 (the short one) the the other is MK?. will they work on my gun?

Quote:

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Originally Posted by locchau

I ordered the MK2 recoil spring from BRP Corp Store today, will get it sometime next week. Where can I find a lighter recoil spring?

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locchau,

IMO I wouldn't be looking for a lighter recoil spring. I wouldn't use any less than the standard double recoil spring .

Joe

Joe,
I meant striker spring and not recoil spring, words seem leaving after few beers. The little binding as I mention on last thread, turn out much worse than I thought it was. After let my machine shop friend examining it, the problem from the receiver gas tube not straight and he said not by much and can easily fix with a new carrier. I got the measurement as you mention on your last threat below. When you drill your Regulator hole, did you use drill bit or end mill bit? The reason I am asking because I do not have tool to heat it up to 1600 Deg F.
Gas Regulator # 4 port: .148
Barrel hole: .149
Gas block exit: .161
Piston: 0.625"
About the Gas regulator, I have a long and a short one. Are they both working the same way? If not which one is the correct one for MK2 Bren? I am ordering a new carrier and MK2 recoil spring, any idea on the striker spring? Should I get a lighter one or use it for now after sorting all of the binding issue.
Loc Chau

I would use the striker spring that you have. It looks good from your photos. My gun came with a worn striker spring that was crushed in a few places. It did not have enough power to push the striker hard enough and I was getting light primer strikes. If you put in a softer spring you might also have light primer strikes too. Only change one thing at a time.

how many of us have gone down this same path ? lots of $ and end up with a non working gun. schnellfeuer and mp44 neither would work without a lot of swapping parts. i feel your pain,both from gun broker :banghead:

Depending on how well the builder copied the Historic Arms design... the new bolt carrier will require significant machine work to convert it to the semi auto version. Eliminating the binding issue might just solve your problem... what parts are binding and where?

Quote:

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Originally Posted by scoobsean

Only change one thing at a time.

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locchau,

Take Scoobsean's advice : fix one thing at a time, locate and solve the binding problem. I'm having a hard time imagining what would be wrong with the bolt carrier that would need replacement.

Whatever the problem with the tube or carrier, get it fixed first then try it out. That may be the only problem:D. If not decide where to go next.

I never realized there was a height difference in the regulators. As far as I know all the MK regulators are interchangeable.

As far as the regulator, I used regular HSS drill bits. HSS will work on the barrel hole and exit hole. The regulator is very hard. If you are only doing one hole you may try a carbide drill bit. It has to be lined up properly. Working with small tooling in hard material is always a problem, you break one or two bits before you learn the right technique. Don't mess with the gas system if you don't have to. Consult your machine shop friend before you do any drilling.

Joe

Scoobsean,

I’ll take your advised and leave the striker spring alone. Right now I just concentrate on fixing the binding problem, and finding way to drill the gas regulator hole. Look like there still lots of work ahead to get this gun to run. Henry B, thank you for your honest commend. This is my first time that I get a none working gun for lots of money and consider myself lucky since the problem seem fixable. My only complaint is that one ought to be honest to stated the working condition of thing they sale, especially something that liability related. Again, thank you all for your help and hopefully I can get this gun to run soon.

Loc Chau

More great advice from single-shot Bren maestro Joe. Just fix one problem at a time, working your way forwards until you get to the end. That way as you move on, you know you have eliminated all the previous problems

Joe, Wally and Peter,
From my machinist friend, the problem is from the tube and not by much. Drilling the Regulator port may fix it. I attached 3 pictures; one with my finger pointing is where the piston started to touch the gas tube, the second picture is when I press the carrier toward me the binding goes away and third is where the full auto blocking welded (total 4 welded). The carrier milled flat on the side that have the full auto blocking weld and my friend thinks that with a new carrier, he can mill it and leave off a little metal just enough to push the carrier and piston to one side and that eliminate the binding problem. What do you think? My though is that with the gas regulator holes drill may just be enough to pull the piston back far enough for the empty case to come out. If I lean the receiver from one side to the other, the carrier slide in and out easily so the bind is not that bad but with all the springs install it may get worse. Thank you all for taking the time to help me with my problem.

Loc Chau

Loc Chau,

Two points to remember

1- the carrier& piston are as from the factory. In this design the tabs that engaged the receiver body were milled off. There is probably nothing wrong with this part. Any further machining on this part or a new one is probably going to unnecessarily add slop to the carrier -receiver fit.

2- The receiver was torch cut in at least 3 places removing a minimum of 1/4" of steel at each location so that it could be imported to the US as scrap metal.

The carrier was milled in a milling machine. The receiver was welded up by the guy who sold you the gun. Which one is probably screwed up???

My Opinion -- Eliminate the bind by grinding the inside of the receiver (dremel, die grinder, air pencil grinder), only where its binding. Don't depend on the gas system to do job the builder should have done.

Here is the test. Using only the receiver, carrier w/piston and the bolt no springs , striker, lower trigger frame, hold horizontal then rotate vertical. The bolt & carrier should slide totally forward and the bolt should lock up with the locking shoulder. No springs, no finger pushing or screwing around. If it doesn't there is a problem.

Below is your pic lightened up. Your pointer is right where there is quite a bit of welding.


My 2 cents,

Joe

Also worth remembering here is that the piston MUST articulate on the piston extension. It is made this way. There MUST be some movement between the two. The criteria for this articulation was that when the gun is assembled, the piston should not foul with the body as it enters the gas cylinder which is tapered inwards to allow for a smooth entry.

Quote:

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Originally Posted by Peter Laidler

Also worth remembering here is that the piston MUST articulate on the piston extension. It is made this way. There MUST be some movement between the two.

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This still holds true with the FN MAG 58/C6/M240B series even today, curiously the FN Minimi/C9/M249 uses a totally rigid piston and somewhat sloppy fit in the sheetmetal gastube.

Joe,

I did the test, the bolt and carrier slide in/out and locking as it should. I try uploading a video that I recorded but no luck, maybe the file too large. I am now trying to get some drill bits so I can drill the Gas regulator.

Loc Chau

Hi all,

Just to give you all an update. Have the gas regulate and barrel hole drill per Joe information on both 7.62x54r and .303 barrels, and replace the recoil spring to the double mk2 spring with some good progress.
Barrel hole - .196"
Gas vlock exit - .196"
Gas regulator #3 - .1695"
#4 - .185"
the 7.62X54r have no problem extract the empty case at #3 setting (.1695") while the .303 still having problem to extract empty case at the largest setting (.185"), thought the bolt and carrier move all the way back but still not enough to extract empty case. How large of the barrel hole can I drill for the .303 barrel? have any one use bren mag for 7.62x54r? if so what modification that I need to do to the mag? I have problem with the ZB39 mag only load one or two rounds to the chamber then the bullet tipped down (up) to the mag.

Loc Chau

Quote:

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Originally Posted by Sentryduty

somewhat sloppy fit in the sheetmetal gastube.

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(Understatement of the day) The whole barrel is loose as a goose's butt...

Browningautorifle,

Thank you for your replied. Is that mean that I have a bad barrel?

Thank you

Quote:

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Originally Posted by locchau

Hi all,

Just to give you all an update. Have the gas regulate and barrel hole drill per Joe information on both 7.62x54r and .303 barrels, and replace the recoil spring to the double mk2 spring with some good progress.
Barrel hole - .196"
Gas vlock exit - .196"
Gas regulator #3 - .1695"
#4 - .185"
the 7.62X54r have no problem extract the empty case at #3 setting (.1695") while the .303 still having problem to extract empty case at the largest setting (.185"), thought the bolt and carrier move all the way back but still not enough to extract empty case. How large of the barrel hole can I drill for the .303 barrel? have any one use bren mag for 7.62x54r? if so what modification that I need to do to the mag? I have problem with the ZB39 mag only load one or two rounds to the chamber then the bullet tipped down (up) to the mag.

Loc Chau

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Loc,

If I'm reading this correctly the barrel hole is .196" and the exit hole is .196" but the gas reg hole #4 is .185" (you drilled it to .185"?). The original Bren barrel hole was .150" as was the #4 port, exit was .196". You current barrel hole is .196" which is the same as the original exit hole.

If the barrel hole is .196", did you drill it to .196" or was that the way you received the barrel? I have heard that historic Arms Brens had the gas system opened up for semi operation. Sounds like maybe the gas system may have been originally set up for a max .196" port and somebody stuck an un-drilled original regulator on the barrel. Did you check all the ports on your regulator for hole size?

If the barrel port is .196" then the #4 port should be .196" to get the maximum from the gas system. The 7.62x54R is a higher pressure cartridge so it will run on a lower gas setting.

As far as the mags are concerned. As far as I know there was never any hi capacity mag designed for the 7.62x54R. The ZB 39 mag will get you 10-12 rds without modification.

Here is a discussion on the magazine issue:

https://www.milsurps.com/showthread.php?t=46085&page=1

Use the link I provided in the thread above for additional info.

Joe

Joe,
Thank you for your replied. To make thing clear both barrel and gas regulator were unmodified when I get the rifle, then I drilled the barrel hole and gas regulator per your trial information below:
Barrel hole - .185" #13
Gas block exit - .196" #9
Regulator #1 - .1285" #30
Regulator #2 - .147" #26
Regulator #3 - .1695" #18
Regulator #4 - .185" #13
Unsuccessful extract the empty case on the .303 still, and without trying the 7.62X54r we then drill the barrel hole, gas block exit and the #4 regulator hole to 0.196”. Yesterday at the range and the result as I stated above with some improve but still not 100%.
.303 barrel: everything set at 0.196” still not extract the empty case but the bolt and carrier slide back to the arrow as picture below, while the bolt only came halfway back before. If the bolt slides a hair more backward until the back of the case hit the piece at the red arrow, it will extract the case.


7.62X54r barrel: Barrel hole drilled to 0.196”, Gas block exit drilled to 0.196”, gas regulator set at 0.1695” and the gun extract the empty case without problem. What is your thought? Wolf .303 ammo loaded too light? Gas issue still exists? should I order another barrel to try out? Should I cut a couple of turns on the striker spring?
Loc Chau

locchau,

If that Wolf ammo is steel cased; the first thing I would do is get some PPU or S&B brass cased 303 FMJ ammo.

54r is a higher pressure round than the 303 so if 54R is working at .1695" 303 should IMO work at .196". Unless the chamber is corroded, I wouldn't be looking for a new barrel, it's something else.

Joe

Joe,

Thank you for your quick responded. Yes the wolf ammo that I used is steel case and none corrosive commercial ammo. I will order some ammo as your suggested and try them out this weekend, and will post an update result. Thank you Joe and everyone for your generous help.

Loc Chau

It sounds like it’s working with 54R. I would be happy with that and not bother with the .303 barrel.

ZB39 magazines work fine for me. I get 18 to 20 rounds of 54R in them.

The gun looks very dry in the picture. Are you oiling it up good? The Historic Arms design puts more friction on the internal parts, so don’t be shy with the oil.

Are you using the same bolt for .303 and 54R? If so, what is the size of the pocket that holds the case rim?

If you really want to use .303, try some other .303 ammo, like PPU or S&B 180 and 175 grain. Do not use Remington UMC. That stuff couldn’t pull a greasy string out of a cat’s ……

If that doesn’t help, cut one coil at a time off the striker spring.

If it still will not extract, you could try lubricating one round. If it extracts it might be worth trying another barrel. I would NOT make habit of lubricating the ammo.

If you get another barrel, be sure you check the headspace before you shoot the gun. You might have to change the locking shoulder to get the correct headspace with a new barrel.

Any changes you make, like cutting down the spring might give you trouble later with 54R.

Quote:

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Originally Posted by Vincent

ZB39 magazines work fine for me. I get 18 to 20 rounds of 54R in them. Any changes you make, like cutting down the spring might give you trouble later with 54R.

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Vincent,

Interesting about the capacity of the ZB39 capacity for 54R. I've only been able to get 13-15 on a good day without mods. Then again I've heard from others that, like you, they can get upwards to 20. I wonder if there are some manufacturing variances that make the difference or is it differences in the rounds themselves ??

I've also found that the berdan primers on the 54r require more "punch" than the new primers on commercial ammo.

Joe

Quote:

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Originally Posted by browningautorifle

(Understatement of the day) The whole barrel is loose as a goose's butt...

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Does give them a nice wide beaten zone though...

Vincent,

I have no luck with the ZB39 mag that I got. Its either not load the first round or only load and shoot the first one, two round at most then the bullet tip down into the mag. I oil the gun very well with break free CLP before and after shoot it, just clean it for pictures. Yes I use the same bolt for both calibers and it is the only bolt that I have. I just order PPU 174gr FMJ ammo from Aim Surplus, hopefully they will get here before Friday. As soon as the ammo get here, I will try it and will follow your comments if it still not working out. I’ll first try to polishing the .303 barrel chamber today after I get off from work before cutting the striker spring since I have tried to order a couple of spare from Mr. Savage but he don’t have any in stock. Anyone here have Historic Arms Bren with spare striker spring and one to sale one? I’ll be more than happy to take it. By what you said there is headspace involve on replacement of barrel, I probably hold off on that because I do not have any headspace gauge and don’t much about Bren to be able to do that by myself.

Joe and vincent, this is a dumb question but how do I disassemble the ZB39 mag. Is the bottom floor plate slide out just like AK or AR mag?

Loc Chau

Loc Chau.

On the top of the mag there is a little dimple. Press it down with the tip of a cartridge or small screwdriver. With it pressed down, slide off the top plate. It will only slide off one way, it's tapered.

Clean it out and oil it. My best guess is that the outside case is pushed in and its binding the follower. Check and be sure you can pull the follower up and down in the case by the spring without binding.

Another thing to check is the overall length of the cartridge. The ZB39 was made for a 8x56R which has a length of 75.91 mm. The 7.62x54R is 77.16mm. The ZB39 mags I have have ample clearance for the longer 54R round. Possibly your 54R is over length.

Joe

Quote:

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Originally Posted by Sentryduty

a nice wide beaten zone

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I have a long story about that for you sometime. It dates back the the first guns we received...and trying to zero them.

Joe,

There is quite a bit of variation in 54R length. I think 54mm is supposed to be the max case length. They all seem to be shorter than 54mm and since it is a rimmed cartridge, it doesn’t matter if the case is a little shorter.

On paper there is a difference between 54R and 53R case lengths. The manufacturers are supposed to round up or down to the closest mm. But that’s in a perfect world. In reality 54R and 53R can have the same case lengths.

There is also variation in bullet lengths. When combined with a shorter case it can be significant.

Lahti-Saloranta M/26 7.62x53R mags will also take some of the shorter 54R. I don’t remember how many rounds will fit.

The primers are hard, but they last forever.

Loc,

Be sure you are not putting the rounds in too far back in the magazine. There is a space at the back of the mag that’s wide enough for a round to fit if you push hard. The rounds go in forward of that, where the mag is wide enough to take two rounds.

I have been told that the Historic Arms striker spring is a stock unit from McMaster Carr. Search their web site and match your spring's characteristics to theirs.

Quote:

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Originally Posted by Vincent

Lahti-Saloranta M/26 7.62x53R mags will also take some of the shorter 54R. I don’t remember how many rounds will fit.

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Vincent,

Awhile back I got a few of those 20 rd Lahti mags ($5/ea) thinking they could be altered to fit the Bren. The 54R I had wouldn't fit in them. There was a strap that could be removed so that the longer 54R would fit but there were so many other problems I stuck with the ZB39.

There is a very long thread over on the Weapons Guild about trying to use the Lahti mags for other rifles but from what I could tell nobody had much luck.

Joe

Hi all,

Thank you all. Just finish polished both chamber last night, will try to work on the ZB mag tonight. Thank you Joe for the mag disassembles instruction. Vincent, I have noted that the round will go all the way back to the mag as you mention and will not feed. I made that mistake once :D. WallyG, I’ll check McMaster Carr to see if they have the spring or something close enough that I can use for experimental. Now I just wait for the PPU ammo from Aim Surplus hopefully before this weekend so I can play with the Bren since I have 3 day weekend because of July 4th Holiday. Wish you all have a good week, will post update of how thing goes along.

WallyG, found the springs that are close enough for me to try. I order two different one, if they work I have spare for anyone who need it.

Loc Chau

Hi every one,
Hope everything going well for all of you, just want to give an update on the Bren. It’s been awhile since my last range time due to get the kids out to the beach and work around the house. Last weekend I finally have the time to take the Bren and some of my rifles out to the range and the result is very promising. First try the Bren with 7.62X54r with the mag mod per Joe instruction and it works great, although I only try the mag with 15 rounds. I shot 3 mags of the 7.62X54r and the 4th mag I try lacquer coated ammo and it does not like it, I have stuck case in the chamber. Next I try the Prvi Partizan .303, 174 Gr brass case and the rifle works perfectly fine. I shot about 4 boxes of the .303 ammo and the trigger stop reset, it acts like the safety is stuck in on position. I have to look at this problem, my guess is just the trigger assembly but I am very happy with the way the gun performs. I am making progress every day, thank you all for your help and support. Will be update again on the next range time, you all have a good day.

loc,

Glad to hear you are making good progress. Keep us updated.

Joe