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Has anyone had success with this? I managed to modify AK magazines to work in the Bren and installed the chinese barrel, ejector, and gas regulator.
I can get the gun to feed and fire BUT it won't cycle to feed the next round.
Forgot to mention, also installed the Canadian 8mm bolt
John, this is a gas problem. There isn't the remotest chance in hell that there'll be sufficient gas to operate the workings AND the system. If the gas block were further to the rear it might do something but.............. we're going into the maths of it now and I've always stood clear of ammo.
Now 762 x54R would be entirely different. Bags of power in reserve there....
It would probably work with blanks if you restricted the barrel enough.
With live rounds that wouldn't work to well though..................
I did a 7.62x39 conversion for a local fellow of a 7.7mm Japanese Type 99 LMG 10-15 years ago by sleeving the chamber (in retrospect it would have been "easier" to do the entire bore!) and opening the gas port to almost twice it's original diameter. It tends to "copper up" the gas system, but itseems to be OK for a day's shooting. Haven't talked to this guy in a long time, but last I heard it was fine.
Lot's o'work to get it all "happy"! Don't think I'd want to do another, but I understand that's not all that uncommon amongst Japanese LMG shooters.
Peter, the conversion did work for the chinese, since the bits,
Barrel, gas regulator, and ejector ARE chinese, or modified by them.
Now I do have a couple of extra return springs, and I am wondering if they used one with less coils on it. There is a point,however, where adjusting the spring might make the bolt travel back far enough to engage the sear, but there might not be enough force to strip a round and fire it, if the return spring is weakened too much.
JohnQuote:
Originally Posted by John Sukey
Was Looking for some info and found this, click on link and scroll down to the bottom of the page were the comments are (Brock Dittrick) mentions the chinese conversion, had another page with more info but closed it down by mistake and cant find it.
Bren Mark I Light Machine Gun, Bren Mark III, Bren Mark IV
Read that, but it doesn't give any technical details. I guess I will just have to experiment with my spare return springs. The chinese modified gas regulator has larger holes than the .303 or 8mm one, I would think to divert more gas pressure to the piston.
It must have worked or they wouldn't have bothered.
It's not just the gas regulator but the barrel vent too. But the gas loss from that cartridge to accommodate/equate to the........... anyway, I wouldn't mind betting that the drop in MV will be horrendous.
We did all sorts of things to AK's (7.62 x39 again) at Shrivenham and while not quite answering the question, I use the maths/dynamics while teaching here............
Not being a pessimist John, but a realist.
But consider that the barrel has also been modded by the chinese. I have not miked the barrel vent.
I really am not worried about muzzle velocity since I am not going to take it to war. Just want it to work so my "friends" will stop using my .303 ammunition. Especially one of them who tends to hold down the trigger too damm long.;)
Just in passing, A friend who now lives in Tucson, Derek Kinne GC, was a Bren gunner on Gloster Hill, captured by the chinese, and deemed "reactionary"
When in hospital, an officer said to him I really shouldn't be telling you this, but you have got the GC. Still a bit out of it, he replied "Oh I was hoping for a MM":lol:
The other GC was posthumous to an officer.
Sorry to drag this up from the depths, but I cant seem to find a x39 Bren barrel anywhere
Am I looking for the wrong thing?
You pretty much will have to do your own!
I converted a Type 99 Japanese LMG barrel for a fellow once. I'd rather not do another!
Happy to see you post, Spanners! What took so long?
You mean 2 years lurking was too long? LOL
What about mags - I presume you use a AK mag >?
Yup. There were kits for these some time back. Forget who did the parts for the mag adaptor, sorry!Quote:
Originally Posted by Spanners
7.62x39 in a Bren will be like trying to run your 2,500cc Triumph using a single 1.25" SU Carburettor. You mark my words
Oddly, the Japanese Type 99s seem to run OK if you can get them to feed. And given the dearth of Type 99 magazines, and to a lesser degree, 7,7 Japanese ammo, combined with very reasonable weapon prices, it was merely a sad pragmatic way of making a shooter out of what was otherwise a bizarre chunk of metal sculpture.Quote:
Originally Posted by Peter Laidler
Seems a bit mad to do it to a Bren.
It's bad enough using 2 SU carberetter!
Sent from my iPhone using Tapatalk
That made me chuckle Gary.......... But you get my drift - and the analogy! Put simply, it's all about breathability with a good dollop of Boyles law and that other law about springs (whos name I forget now) thrown in for good measure. You might get it to FUNCTION, but how it performs is quite another matter
years ago. I seen some information on the chinese bren and if I am remembering correctly the gas piston is a smaller diameter.
My example was just a bog standard 8mm John Inglis Chinese contract Mk II Bren with the magazine adapter/ejector block, AK magazine, and the chamber sleeved and rechambered to 7.62x39. The painted markings on the butt translated to Navy (Peoples Liberation Army, Navy). I never shot it and sold it a few months ago to a specialised ChiCom collector. The piston and bolt were unaltered except for an ejector clearance cut in the upper rear surface of the bolt. I assume they just used the larger gas regulator holes for reliable operation.
Small Arms Review did a article on the Chinese Bren 8mm a while back but unfortunately I can't say when. It was a few years ago.
To be really honest - and diplomatic, I'd say that anyone who was seriously considering converting any of the Brens to 7.62x39 and expecting any sort of mechanical reliability was pis............er....., urinating into the wind to coin a well used English phrase
John: Two suggestions, both based on experience with other (but similar gas-operated) guns that exhibit apparent lack of energy to cycle. Neither may cure your problem but they might. I would regard them as the sine qua non of getting any gun not originally designed for 7.62x39 to work properly.
First, considering yours is a Chinese barrel, probably made in the days when clumsy conversions were improvised because China didn't have the resources to provide its troops or militia with more suitable arms: Take the barrel outdoors and closely examine the chamber with the bright Arizona sunlight shining in from behind you. If the chamber walls are anything but unfouled, white-bright and unpitted, especially down in the neck/shoulder area, you will need to make them so. If the chamber has patches of yellow-brown scum, get rid of them with a .45 stainless bore brush chucked into an electric drill. Then make a Cerrosafe chamber cast to detect any bulge, eccentricity or surface anomaly that might be retarding extraction. It's also a good opportunity to check the chamber dimensions for anything out of whack.
Second, you didn't say what kind of 7.62x39 ammo you were using, but the Chinese almost surely were using steel-cased ammo in this conversion. Brass-cased cartridges (often favored by MG shooters simply because it's usually NC) tend to be softer than steel and when fired will adhere more tightly to the chamber walls --again retarding extraction and giving short-recoil symptoms that are easily mistaken for insufficient gas.
M
The Chinese conversion of the ZB 26 in 7.62 x 39 works well, however we are looking at gas trap as compared to ported. The one illustrated in The Bren Gun Saga vol.2 works well with both steel and brass cased ammo.
Nice to see you here MGMike and hope all is well down your way.
Hmm...I have a parts kit of one of the Chinese converted Brens that I'm sending out to have built in a couple months. I've talked to folks with functional Type 99 Nambus and ZB-26s in 7.62x39, and I was hoping the Bren would be do-able as well. I guess I'll find out! I even managed to find a ZB-26 magazine converted to feed 7.62x39, in place of the more common AK mag conversion:
Unusual Chinese ZB/Bren Magazine
https://www.milsurps.com/images/impo...2mag6JPG-1.jpg
The main problem here that I see is what we call 'the twilight zone' where the round if not under control. That is neither controlled by the magazine or the chamber. That spells bad news and the perfect recipe for a jam. That;s the very reason for the major difficulties/problems converting the Bren to 76.62mm and the reason why the magazine has to be moved so far forwards. And it was this that caused the major head and heartaches. It was finally cured in a novel way........................ And not be creating a 'twilight zone'
ForgottenWeapons,thanks for the post about your mag and the link to the other pictures.....very interesting.
What are the markings on the spine of the mag ?
Are there any markings on the conversion parts ?
Have your tried any 7.62 x 39 rounds in it ? ......just wondering also if 7.92 x 57 crimped blanks would also fit ?
With this setup the rounds are further back than the AK mag conversion so the small 7.62 x 39 rounds vent off gas is going to have to work overtime to push the working parts back that extra inch to cycle the next round or to capture and hold the piston extension.....plus another inch of friction :-)
Good luck with your conversion and let us know how it goes.
ATB Kevin
I don't recall the markings on the conversion parts, and they're a bit packed away right now. The magazine (which I found separately) is numbered "186" under the front lug and has what appears to be a small stamp of three interlocking diamonds on the spine (no German markings).
I have tried x39 rounds in it, and the feed lips are a bit loose but the length is perfect. It'll hold about 15 rounds before they start to act up because there isn't any curvature to the magazine. I would be surprised if it will feed reliably with more than 10 or 12, though. Guess the only way to find out for sure is to get the gun built! :)
I really want to find an 8mm Bren barrel to go with the kit, so I can shoot either cartridge.