Gunsmithing Method for Installation of a Muzzle Brake?

[mattmcg]

I need a bit of guidance on how to install a muzzle brake on a particular rifle of mine. The barrel is a Krieger heavy palma with a 5/8-24 threaded muzzle. I have a JP muzzle brake that I would like to install that is also 5/8-24 threading.

How would you go about installing this? The muzzle brake needs to be indexed and is currently overshooting the center by about 45 degrees (see pic 2).

I believe the options I have are:
1. Trim back the brake to fit it to the barrel
2. Use a crush washer
3. Have a shim made of exact length and width
4. Thread the barrel back further to have it fitted

I'd love the option of removing the brake and installing the muzzle cap if at all possible (which would negate option 4). I'm an amateur when it comes to this stuff and would appreciate your expert guidance.

Pics:

 

[wnroscoe]

Re: Method for Installation of a Muzzle Brake?

While in the lathe I just trim the barrel shoulder back until the brake times right. I've seen the rear of the brake trimmed to do the same but again, a lathe was involved. Trimming the back of the brake may be the easiest if you have a lathe as the bore of your barrel would need to be re-indicated to cut the barrel shoulder. If you have a three jaw that runs true cutting the brake shoulder would be a quick fix.

 

[Hateca]

Re: Method for Installation of a Muzzle Brake?

I wouldn't even consider a shim or crush washer like on an AR-15.

You're only option is to either turn the shoulder of the brake or that barrel and this will require a lathe. Trimming the brake shoulder would be the easiest but then that all depends on how long the shank of the barrel threads are compared to the brake. You don't want the end of the barrel extending into the first expansion chamber.

If you plan on removing this brake repeatedly plan on it becoming over timed down the road. Timed or indexable brakes are not meant to be repeatedly removed. Any indexable brake I recommend be installed with a little loc-tite to hold them steady. Too much torque can cause you issues with the bore and crown.

 

[jaw921]

Re: Method for Installation of a Muzzle Brake?

I just got my jp tactical comp. and it came with a crush washer. I put it on and it had the same problem you have, both with the crush washer and without. So I grabbed a different crush washer from one of my other rifles and presto, it was perfect. I would like to have a more clean look where the barrel and comp meet, without the crush washer. If you can do it, I would say #1 trim the brake, but I'm no expert, it's just the first thing I would try to do.