Bren 2 9" FTE/Stovepipe issues

[czkyle1776]

I'm hell bent on getting this rifle to run reliably.  I will even get a new gas port drilled in the "0" setting that is smaller to test overgassing theories. 

I am gonna call my buddy in the Czech Republic later today who works for a CZ LE dealer and see if he knows of anything regarding these guns on that side of the pond.

I should also be able to talk to the CZ-USA "Bren 2 Parts Guy" today.  I'll see what I can pull out of him.

I'm so happy people are so dedicated to fixing the issues that CZ clearly doesn't care about. Hopefully someone figures something out before mine arrives. I put off purchasing a couple other guns because I'm in love with CZ and had to make sure I'd be able to buy a Bren 2. Super dismayed with what I'm reading since I got the 7.62x39 version.

[czfanatic_]

I'm hell bent on getting this rifle to run reliably.  I will even get a new gas port drilled in the "0" setting that is smaller to test overgassing theories. 

I am gonna call my buddy in the Czech Republic later today who works for a CZ LE dealer and see if he knows of anything regarding these guns on that side of the pond.

I should also be able to talk to the CZ-USA "Bren 2 Parts Guy" today.  I'll see what I can pull out of him.

I'm so happy people are so dedicated to fixing the issues that CZ clearly doesn't care about. Hopefully someone figures something out before mine arrives. I put off purchasing a couple other guns because I'm in love with CZ and had to make sure if be able to buy a Bren 2. Super dismayed with what I'm reading since I got the 7.62x39 version.

These are the only guns I own with the exception of my carry gun which is a Sig P365XL.  I've got almost 10 CZ's and they have all been fantastic.  This is the only one that has given me any sorts of issues.   

I will get this gun running, and hopefully get others running along with mine!

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[czkyle1776]

I'm hell bent on getting this rifle to run reliably.  I will even get a new gas port drilled in the "0" setting that is smaller to test overgassing theories. 

I am gonna call my buddy in the Czech Republic later today who works for a CZ LE dealer and see if he knows of anything regarding these guns on that side of the pond.

I should also be able to talk to the CZ-USA "Bren 2 Parts Guy" today.  I'll see what I can pull out of him.

I'm so happy people are so dedicated to fixing the issues that CZ clearly doesn't care about. Hopefully someone figures something out before mine arrives. I put off purchasing a couple other guns because I'm in love with CZ and had to make sure if be able to buy a Bren 2. Super dismayed with what I'm reading since I got the 7.62x39 version.

These are the only guns I own with the exception of my carry gun which is a Sig P365XL.  I've got almost 10 CZ's and they have all been fantastic.  This is the only one that has given me any sorts of issues.   

I will get this gun running, and hopefully get others running along with mine!

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Not all heroes wear capes...... Unless you do. In which case....carry on.

[czfanatic_]

In case folks are curious, here are pictures of my destroyed 7.62 extractor compared to my 5.56 extractor which has like twice as many rounds on it. 

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[czkyle1776]

In case folks are curious, here are pictures of my destroyed 7.62 extractor compared to my 5.56 extractor which has like twice as many rounds on it. 

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Do the 556 and 762 guns use the same gas port? Are the holes the same? I would think they shouldn't be, but would it work to swap the gas selectors to see if different sized holes make a difference?

[czfanatic_]

Wow, ok, first off let me say that I am pretty livid right now.

I just got off the phone with CZ customer service, and explained my situation.  I forget the name of the person I spoke with yesterday, so he takes down all of my info again (apparently they can't look anything up), and proceeds to tell me that they WILL NOT SEND ME AN EXTRACTOR, AND THAT I NEED TO SEND THE ENTIRE GUN IN FOR REPAIR. 

I am FURIOUS. 

I am not sending this gun to them, no way.  They are going to send me an extractor. 

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[America_First]

Wow, ok, first off let me say that I am pretty livid right now.

I just got off the phone with CZ customer service, and explained my situation.  I forget the name of the person I spoke with yesterday, so he takes down all of my info again (apparently they can't look anything up), and proceeds to tell me that they WILL NOT SEND ME AN EXTRACTOR, AND THAT I NEED TO SEND THE ENTIRE GUN IN FOR REPAIR. 

I am FURIOUS. 

I am not sending this gun to them, no way.  They are going to send me an extractor. 

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This situation with CZ-USA and the Bren 2 7.62x39 fiasco gets worse by the minute. 

They want you to go through all the hassle of shipping an entire firearm - to swap out a $35 extractor that takes less than a minute to do? 

[czfanatic_]

I just got into it with the customer service manager.  I'm supposed to be getting a call from someone in the actual warranty department. 

I am so ticked off right now. 

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[America_First]

This is not how CZ-USA wants to proceed if they intend to continue to sell $1,600 - $1,800 Bren 2's in 7.62x39 here in the United States. 

[MeatAxe]

In case folks are curious, here are pictures of my destroyed 7.62 extractor compared to my 5.56 extractor which has like twice as many rounds on it. 

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Yikes! Looks way over gassed, probably too big a gas port in the barrel or maybe on the gas regulator.

CZ really needs to get their parts and service together on the Bren 2. This is inexcusable.

I tried to post a poll on here to see how prevalent this problem is, but it failed to take. I am a luddite anyway.

[GypsyDanger]

CZ needs replacement gas regulators sent to everyone, and proper chrome silicone 5-coil extractor springs. Or have a dual spring extractor setup like the lobster tail extractors on LMT E-BCGs. I think the gas port being right at the muzzle and lack of dwell time contributes to those issues. Maybe a teeny tiny gas port upgrade and a suppressor would help alleviate these issues, by decreasing gas port pressure and increasing dwell time?

My 9" 7.62 SBR had a few stovepipes early on, but those issues have gone away (for now). Have close to 800 rounds downrange.

[Mercs]

Maybe I’m a dummy but I am wondering now if perhaps the issue lies in the conversion, and whether the bolt carrier is lighter than the FA version, but they left the gas ports sized the same? Perhaps the rail has nothing to do with it, but the round count does, and once it breaks in the bolt speed exceeds the functional range?

IF that’s the case then either a weight buffer of some sort, or decreased gas port size, or stronger return spring might help


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[Magsz]

Maybe I’m a dummy but I am wondering now if perhaps the issue lies in the conversion, and whether the bolt carrier is lighter than the FA version, but they left the gas ports sized the same? Perhaps the rail has nothing to do with it, but the round count does, and once it breaks in the bolt speed exceeds the functional range?

IF that’s the case then either a weight buffer of some sort, or decreased gas port size, or stronger return spring might help


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Good theory bud.  I think you're probably on to something there but i'm not sure if the weight difference on the FA version is significant.  I actually think the FA bolt may be lighter due to the cutout for the auto sear but that is PURE speculation.

I think CZ screwed the pooch with spring rates and gas port sizes, period.  The "butt dyno" leads me to believe that ALL barrel lengths use the same recoil spring rating as well as the 5.56 and 7.62X39 guns sharing the same.

Anyone that has spent ANY time around varied barrel lengths on any AR15 knows that there is no one size (rate) fits all optimal spring.

[czfanatic_]

Maybe I’m a dummy but I am wondering now if perhaps the issue lies in the conversion, and whether the bolt carrier is lighter than the FA version, but they left the gas ports sized the same? Perhaps the rail has nothing to do with it, but the round count does, and once it breaks in the bolt speed exceeds the functional range?

IF that’s the case then either a weight buffer of some sort, or decreased gas port size, or stronger return spring might help


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Good theory bud.  I think you're probably on to something there but i'm not sure if the weight difference on the FA version is significant.  I actually think the FA bolt may be lighter due to the cutout for the auto sear but that is PURE speculation.

I think CZ screwed the pooch with spring rates and gas port sizes, period.  The "butt dyno" leads me to believe that ALL barrel lengths use the same recoil spring rating as well as the 5.56 and 7.62X39 guns sharing the same.

Anyone that has spent ANY time around varied barrel lengths on any AR15 knows that there is no one size (rate) fits all optimal spring.

I can confirm that the recoil springs in my 9" 7.62x39 and 11" 5.56 are exactly the same, which seems strange.

I'm starting to think that another option we may be able to pursue on our own is drilling out the "0" setting on the gas port.  Start small, and work progressively larger.  Would have the added benefit of running better with a can too in theory.

[America_First]

How can CZ-EU & CZ-USA not get this right, when Krink's have existed virtually forever and are bomb-proof in reliability. 

I'm going to run a few hundred rounds next time out, with the CH on right hand side.  Make sure I tap the charging handle to verify it locks after each magazine change.  I'll also shoot a few rounds on the suppressor setting to get a good idea on where to drill. 

I'll make sure to report back, as of right now, the answer from CZ-USA ["buy brass-cased 7.62x39"] just isn't going to cut it.