Looking for a good brake, possibly AK 47 type, that will screw directly onto a model 1 20" 7.62-39mm H-barrel. I'm not sure what threads it has , or how to deturmine what they are. Thanks in advanced for your help. Binford.

I think the Model 1 barrel threads are 1/2x36.

I also think 1/2x36 is standard for 7.62x39 and 9mm barrels to prevent the 1/2x28-threaded comps for 5.56 from being accidentally installed over a too-large bore.

The only comp I know that comes in 1/2x36 is by Smith.


Several retailers carry it for $35-50.
Brownells lists everything but the 7.62x39 model for $35,
but here is the cheapest I found assumedly in stock:
AR15 7.62 x 39 Pre Ban DEL-SE319$40.00

Never ordered from these people before... any input?

Cheers, Otto

I forgot to add that KKF advertises that it can thread any of its brakes to 1/2x36 and/or the appropriate exit diameter.

KKF Products/Services

Standard supplied threading is 1/2-28. Also available for 30 & 35 (9mm) calibers. Colt threading (1/2-36) is also available, as well as special threadings of 9/16-24 & 9/16-28. Contact us for details.

Cheers, Otto

Thanks for your help! I posted this on four different boards, including Model one's forum, and yours is the only response so far.

As somebody who's had a model 1 7.62x39 barrel (ditched it because it would not close a go gauge), I can say it is threaded 1/2x28 and I put the exact break you're talking about on it.

Very effective.

The standard AR A1 or A2 flash suppressors are 1/2x28 thread -- if you have one of them around, you may want to try installing it.  If its 1/2x36 thread on your barrel, the A2 F/S will go on about 1 turn (finger pressure only) and stop.
But if the F/S you have came from the 7.62x39 barrel originally, that won't tell you much.

Model1 may have their own system for threading their barrels, and I have no clue re: thread vs. caliber.
I do know that their new 6.8 SPC barrels are 1/2x36 for I called them with my own question after my A2 F/S did exactly as above.
I get through to a person with an answer about 50-60% of the time I call the (847) 693-3192 number on their catalog, so you may want to try that instead of their email -- my experience is the same as yours.  Not a criticism, per se, for I imagine they are a small shop with increasing business and limited staff.  More power to them for I like their prices and options and have had very positive experiences on balance.

Frisco: Are you talking about the Smith or KKF brake?

My buddy and I each want one for our 6.8 barrels, figuring the .277 vs. .308 or .311 bore sizes won't matter much for a .30 cal. brake due to the increased powder capacity compared to a 7.62x39.
Now to find ammo for the darned thing.

Cheers, Otto

Yes, it is a Enterprise AK-74 Muzzle Brake on a 11.5" barrel for my M16.  Runs like a champ, really loud and has a huge fireball...I have some video somewhere and I'll post it once I find it.

Edited to add:  I did have to have an adapter made to fit the brake to the muzzle thread of the barrel.  14mm-1.0 LH to 1/2x28

Hey Frisco! How's the AR47 running for you? Are ya still happy with the lower? Buy the way did you have Michael's do the machine work too? I neglected to ask before?.                                                                                                                          Binford

Happy as can be....The last machinegun shoot, I dumped 1000 rounds before I took a break.  

Barrel was red hot, noise was way loud, but was a ton of fun.

It spits fire also!

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