Serious MK12 issue please help...

[BirkGun]

Hello All,

1. I bought an Allen Engineering brake and collar for the mk12, it came and I proceed to put the brake on the muzzle of my rifle , which has the profile for the MK12 from Precision Advantage. The brake twists on 4 times then hard stop.

2. I tried the brake on another no name 1-2/28 thread AR barrel and it went on fine.

3. I contacted Allen Engineering and Mr. Allen sent me another brake, result same as above.

4. Frustrated, I went and bough a MK12 barrel from Compass Lake Engineering,

5. Same issue!

I'm super frustrated, arn't Compass Lake Engineering one of the provider for the real MK12 barrel, and the barrel suppose to take the Ops Inc now Allen engineering brake and collar with no issue?


Can someone recommend me a gunsmith to tell me what the freak is going on? They are all 1-2/28 thread!!! please help.

[Pofoo]

Sounds like your barrel thread is out of spec.
Barrow/buy a die and chase the threads.

[edgerly779]

Contact ar15 barrels Randall on here. Hard to refer a local when you hide your location.

[ar15barrels]

Can someone recommend me a gunsmith to tell me what the freak is going on?

I know a guy.

[BirkGun]

I just want to thank Randall from ar15barrel , he was great and fixed my issue in no time at all! Highly recommend !

[SkyHawk]

I just want to thank Randall from ar15barrel , he was great and fixed my issue in no time at all! Highly recommend !

Awesome! Don't leave us hanging, what was the final diagnosis?

[Sig so sour of ca]

And the issue was.....

[ar15barrels]

Awesome! Don't leave us hanging, what was the final diagnosis?

And the issue was.....

Allen engineering muzzle brake threads were either too small or had some burr that a 1/2-28 tap cleaned out.