Author Topic: Bren Gas tube wear  (Read 1602 times)

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Offline Obiwan

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Re: Bren Gas tube wear
« Reply #15 on: January 27, 2018, 10:49:20 AM »
Could it be metal fatigue on that gas tube? I would just ask CZ to send you the rifle back with a new gas tube. If the problem persists, then it's time to look at the barrel. Gas tube replacement is much easier, so I'd start there.

Offline TURRICAN

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Re: Bren Gas tube wear
« Reply #16 on: January 27, 2018, 03:12:23 PM »
Don't worry so much about the gas orifice size in the barrel. CZ sells a different gas regulator plug for 10", 14", and 16" barrels. I just had my barrel cut down to 14" so I bought the correct regulator and immediately noticed the holes are a different size than the regulator for the 16" barrel.. Making the barrels with all the same size gas orifices and using different regulators to dial it in for the specific barrel length probably streamlined production a bit.

Offline DDNC

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Re: Bren Gas tube wear
« Reply #17 on: January 27, 2018, 04:23:51 PM »
I will shortly have the 805 pistol and soon to be SBR so no hands on experience but I do have a B&T APC556 which is a very, very close relative but a bit smaller with more options and there is no valve port wear. Also I have a several SIG sans guns that have similar valves, also with no erosion.  I mentioned on the files that it looks to me that the Bren valve is chrome plated and possibly that is simply flaking off? Regardless I also ordered a spare valve.

Offline M1A4ME

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Re: Bren Gas tube wear
« Reply #18 on: January 27, 2018, 04:47:33 PM »
Don't have an 805.  The few times I've pulled the gas block/front sight base off an AR15 I've never seen anything like that.

I've had the front sight/gas block on my SIG 556R twice, darn thing looks new.

I've got maybe 300 rounds through my GII and when I took the gas block off to install the adjustable gas block it also looked new.

I've seen pictures of other AR15 barrels at the gas port where it meets the front sight base.  Most of the time people say wear like yours would be excessive.

Even then, about the only time people complain about "gas" to the face is when they run a suppressor on their AR15. 

Is the 805 a DI system or gas piston system?  Only a DI system should even be putting any gas back into the bolt/receiver.
Better to have it and not need it, than to need it and not have it.  So, if you see me walking the dogs with my SIG 556R, its okay.

Offline armoredman

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Re: Bren Gas tube wear
« Reply #19 on: January 27, 2018, 09:08:15 PM »
Piston system. I looked at mine best I could without tearing it down, and it looked fine.

Offline rdcinhou

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Re: Bren Gas tube wear
« Reply #20 on: January 28, 2018, 05:48:30 AM »
What type of ammo were you using?

Some of the really cheap ammo out there can be corrosive:

http://www.czfirearms.us/index.php?topic=43678.0
CZ 24, CZ 27, CZ 38, CZ 45, CZ 52, Vzor 70, CZ75BΩ, CZ75D PCR Compact, CZ 75 P07 Duty, CZ75 SP-01 Phantom, CZ Shadow 2 Urban Grey, CZ P09 Duty, P10C, CZ 82, CZ 83, CZ 97BE, CZ 2075D RAMI, CZ 452 American, CZ 550 UCS (Urban Counter Sniper), CZ 805 Bren, DUO & Z

Offline Wusteadler

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Re: Bren Gas tube wear
« Reply #21 on: January 28, 2018, 10:31:00 AM »
I tried IMI 62gr, Wolf Gold, MKE 62gr, PMC, etc. 10rds of each at a time.

Offline wyoung

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Re: Bren Gas tube wear
« Reply #22 on: January 28, 2018, 11:56:00 AM »
I have an 805 rifle I bought a year and a half ago and an 805 pistol I bought from Bud's a few months ago. I've never had any issues after hundreds of rounds. I'll have to see what mine look like.

Offline fakahatchee

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Re: Bren Gas tube wear
« Reply #23 on: January 28, 2018, 02:39:00 PM »
   Wolf gold in mine, the Taiwan brass cased m193, been using it in all my retro ar's for years with no problems. We might have got a couple of bad gas tubes, bad heat treat or casting?  I'll keep using the original till the orifice opens up over .043 than in goes the replacement. Cz should have offered to replace the gas tube, but even after seeing the photo's of erosion at 400 and 900 rounds they said that it was normal. Here's mine


Offline MikeinCA

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Re: Bren Gas tube wear
« Reply #24 on: January 28, 2018, 03:51:04 PM »
After approx 1.5k rds through mine it has the same erosion to the gas plug chrome plating.

As an FYI a section of Magpul M-Lok rail cover (Type 1) fits securely into the 2 vent holes and will prevent you getting hit in the face with gas blow-by or particles.





Offline Wusteadler

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Re: Bren Gas tube wear
« Reply #25 on: January 28, 2018, 06:16:28 PM »
Great idea, with the port cover!

Offline dso970

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Re: Bren Gas tube wear
« Reply #26 on: January 29, 2018, 01:00:29 AM »
After approx 1.5k rds through mine it has the same erosion to the gas plug chrome plating.



that looks pretty bad...theres no way cz could say thats "normal"

Offline thehun

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Re: Bren Gas tube wear
« Reply #27 on: January 29, 2018, 10:02:26 AM »
What model year are your guns? Maybe there is a bad batch.

Offline Wusteadler

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Re: Bren Gas tube wear
« Reply #28 on: January 29, 2018, 10:52:36 AM »
Couldn't tell ya. CZ has mine still.

So here is my concern.... CZ says this horrible erosion is "normal", but only a hand full of us are having the problem. So if it was normal, everyone's gas tube would look that way. Right?

Also, so what are you supposed to do if it is normal? Spend $80 on a new gas tube every couple hundred rounds? 

Offline thehun

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Re: Bren Gas tube wear
« Reply #29 on: January 29, 2018, 02:42:59 PM »
I haven't measured mine but how thick is the gas plug?

That erosion sucks no matter what but if the material is thick enough and the orifice hasn't opened up...then functionally it is still ok.

I still think its a bad batch somehow...the user that had 10k rounds fired had better gas plug than what is in this thread.