Machinist buddy just threaded this for me. Not quite sure what to do with the gap here. Crush washer? O-ring? I dunno. Also, what about the finish?
Gunsmithing Muzzle brake install.
- Thread starter Doyputasos
- Start date
The only muzzle brake/flash hiders that I have ever messed with were for M4s and I just used crush washers. I do not know if that is your best option here though. Can you tell wether or not there is a gap between the muzzle and the base of the brake?
If it were me, I'd have your machinist face off the brake (or face off the shoulder) a few thousandths until it timed up correctly He should be able to calculate how much to cut based on the thread pitch and where it seats now.
For instance, if it's a 5/8-24, then 24 tpi is 0.0417 thou per turn. You said about 1/16 of a turn to make it tight. That means you need to shave off 15/16 of a turn to get it back to proper timing. 15/16 is .9375. Multiply that by 0.0417 and you get about 0.039. So you need to take 0.039 more cut either off the face of the brake, or the shoulder of the barrel thread (or some combination of both to reach 0.039).
For instance, if it's a 5/8-24, then 24 tpi is 0.0417 thou per turn. You said about 1/16 of a turn to make it tight. That means you need to shave off 15/16 of a turn to get it back to proper timing. 15/16 is .9375. Multiply that by 0.0417 and you get about 0.039. So you need to take 0.039 more cut either off the face of the brake, or the shoulder of the barrel thread (or some combination of both to reach 0.039).
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After re-reading this thread, I realized that I left out a very important detail. The type of break that I purchased has a clamping screw that tightens the brake to the threads so that a crush washer or timing is not necessary. I do know that the break will be on the threads stronger if it butts up against the muzzle of the rifle though. Also, I am still not sure how to finish the muzzle where material was removed. Currently it is just bare metal. I live in the desert where moisture is not a big problem, however I know I need to get it covered.
The threads will rust eventually if you don't coat it with something (oil, blue, duracoat, etc.)
Definitely needs to be timed. The thread shank appears to be a tad too long, and the brake is bottoming out before it indexes on the "crown" of the barrel.
The shank is to long i would send it back to him have him shorten it, recrown if necessary, and then index the brake correctly.
I *can* thread the brake til there is no gap and it hits the shoulder. I have an RWS brake that has the clamp which lets me fix the brake in place where it is indexed properly.
When you're timing these brakes sometimes they can bottom out at the beginning of the threads, especially if the end of the threads is the same as the major diameter. I would chuck the brake in a three jaw and cut a small relief area where the brake's threads begin. It's really easy to chase after the wrong problem.
