Has anyone here racked up time with a Bren 2 yet?

[Aries144]

That's a pretty obnoxious post. Let's try and keep this mature, please.

Over time, magazine over insertion stops wear out. Coming down hard on a gun in the prone can do damage to this stop as well. Under stress, over inserting a magazine is a thing. Not everyone is a cool operator that uses EXACTLY the right amount of pressure to get their magazines to lock in while filming themselves for the 'gram.

I'm a push pull type of guy and as I've said before, I have numerous mags that I've shit canned because the over insertion stops have worn out. To date, this is all relegated to Pmags, never an aluminum or steel USGI pattern. Its a thing, whether you want to believe it or not. The ACR had horrible issues with over insertion of magazines. The Bren is a little bit better but it can still suffer from issues if the mag is inserted on the harder side of the spectrum and that top round vomits out.

Lighten up Francis. Text communication misunderstanding (plague of our era) strikes again. I shouldn't have used the word "you." I mean "one" as in 'one should lay off the male hormone pills.' This wasn't an attack or aimed at you, just the result of a long day and a sudden mental image that gave me a laugh I decided to pass along in illustrated form. I'm not kidding. I wrote "He-man a mag in" and it was all over. It just flowed. 80's cartoons, steroid abuse, Testosterone 5000, vague memories of narrated youtube FLIR cam footage of a native banging a donkey in Afghanistan and everything.

Back on topic: I wasn't talking about over insertion dislodging rounds, just very aggressive insertion. I thought you were inferring that I meant overinsertion, and felt the need to clarify. I had no idea you'd personally broken or overridden multiple overinsertion stops. I've avoided using PMags for anything but practice since one from a bad batch of gen2 FDE pmags caused me multiple double feeds when putting down a sick animal.

In 8 years of bi-monthly 2-gun/3-gun, plus weekly practice sessions, using an AK and later an AR with USGI mags, I never had a mag overinsert. I've seen plenty of USGI mags ruined by people repeatedly slamming the shit out of them on open bolts though, thus my misunderstanding. And the He-man visual. And the warning about male hormone abuse and associated poor impulse control.

[superswamper]

I know it's an old thread, but was there ever any resolution to the 7.62x39 version of the Bren 2 stove pipe and other malfunctions issue?

[Bret]

There was sort of a resolution. They did provide me a gas valve with smaller holes. It helped significantly, but I did have another stovepipe on a spent case this weekend. Aside from the over gassing, I think that another issue is the ejector. Most of the spent cases hit at the rear of the ejection port. They then bounce forward to about 12:30, often hitting the fingers of my left hand which are wrapped around the handguard. In the case of the picture below, the spent case hit the rear of the ejection port, bounced forward to hit the front of the ejection port and then got caught by the bolt carrier going forward. The design of the ejector spring seems odd to me. Why so long? I just don't think it provides enough force to get the case out quick enough.





In spite of the fact that the ergonomics are great, I would not recommend buying one. CZ has failed to support the platform and it doesn't look good going forward.

[Bret]

It's been a year and a half since I posted above, but it's time for an update. After trying to figure it out myself and waiting a few years, I finally sent my 11" 7.62x39 Bren 2Ms back to CZ about mid-March at their expense. A couple of weeks later I received an email that stated the following:
Case Notes: Disassembled firearm completely and inspected all components. Rebuilt breech-block assembly including ejector and spring and extractor and upgraded BCM extractor spring. Re-peened extractor pin into place and polished as needed. Replaced gas plug and piston with new. Polished chamber, feed ramps, and locking lugs. Appears to have been a few issues acting all at once. Took 20 rounds to fully diagnose issues. Test fired 60 rounds S&B 123gr FMJ. Zero malfunctions. Cleaned and inspected firearm. All OK. Total round count: 80 - S&B 123gr FMJ

I have to say that those are the most thorough notes that I've ever received regarding a gun repair. Plus, they invested in 80rds of ammunition. Most gun companies fire 5-10rds at the most and call it good. Hopefully, it's a sign of good things to come. I'm also happy that they didn't try to blame the 7.62x39 AR15 magazines that I've been using.

I received my 11" 7.62x39 Bren 2Ms back two days ago and fired it yesterday. I put 120rds of Tula 122gr FMJ copper jacket through it using a D&H 30rd magazine. I could immediately tell that the ejection seemed different. Ejection was from 2:00 to 2:30 and the spent cases went about 7'. I have a lot more testing to go before I'll be confident, but I'm optimistic.

[Aries144]

Thanks for the update Bret. Would you consider disassembling the ejector so that any differences in ejector or ejector spring could be viewed? CZ's comment about the extractor spring is sufficient, I think. No need to remove and re peen the extractor pin.

I've noted 12:30 ejection on my 9" Bren 2MS and remedied it with an HBI gas cylinder, however ejection distance is only a few feet, 2:30 or so.

I've seen similar issues with an AR-10 type rifle. Ejection was weak and seemed to make malfunctions more common. A profound improvement in ejection was noted after the user began using a dual extractor bolt.

[Bret]

Aries144, As much as I would like to, there's no way that I'll ever disassemble the ejector assembly again. Prior to sending it back to CZ, I tried multiple ways to reassemble it. I ended up damaging the replacement spring that they sent me. I'm sure that I'm not the first person that this has happened to. There's simply no good way to do it short of a special tool or magic. I can't figure out why they made the ejector spring so long.