muzzle brake -- shim vs. crush washer

[hotrail]

Is there any benefit to using shims vs. crush washers to time a muzzle brake? I have a brake I need to install on my Remington 700 PCR. The brake was supplied with a crush washer. I suppose the first step should be to thread the brake on and see how it is timed without.

Do you ordinarily use a bit of thread locker on brakes? Like the blue Loctite?

[MongooseV8]

Shims can be re-used.

[tonyxcom]

No thread locker required with crush washers. Probably not with shims either unless you are running a suppressor.

[vintagearms]

Take it to a qualified gunsmith and have it timed properly. No shim/crush washer needed if done right. Also, no thread locker needed, as it will need to be removed for cleaning periodically.

[Bicky]

Take it to a qualified gunsmith and have it timed properly. No shim/crush washer needed if done right. Also, no thread locker needed, as it will need to be removed for cleaning periodically.

Or, just get one of the self-timing brakes like the heathen or little bastard.

[lordmorgul]

Shims also do not leave gap area, which crush washers do when not fully crushed.


Andrew - Lancaster, CA
NRA Life Member, CRPA member, Calguns.net contributor, CGF / SAF / FPC / CCRKBA / GOA / NAGR / NRA-ILA contributor, USCCA member - Support your defenders!

[DrJeds44]

Shims make for a much cleaner installation.

[bug_eyedmonster]

Or, just get one of the self-timing brakes like the heathen or little bastard.

another option is the Spartan Precision Kopis brake.

https://spartanrifles.com/collections/frontpage/products/kopis-muzzle-brake?variant=18286180335734

[hotrail]

Take it to a qualified gunsmith and have it timed properly. No shim/crush washer needed if done right.

I don't understand the assertion that no shim or washer is needed. How is a "qualified gunsmith" going to get the brake correctly timed without use of shims or washer? Are they trained to just miracle the brake securely in the correct position?
The fact is, unless the threads on muzzle and brake just happen to have been cut perfectly--in relation to one another, and by different manufacturers--such that the brake threads right on and stops at just the right point of its rotation on the threads (which seems unlikely), then is it not inevitable that it will be necessary to time the brake, either with shims, a crush washer, or a lock nut? I guess the other alternative would be to mill some material off of the brake or barrel until the brake is correctly timed. That would be a complicated task, and would mar the finish. But that is why the world uses shims and crush washers, right? Which is what a gunsmith would do...

[mmlook]

I don't understand the assertion that no shim or washer is needed. How is a "qualified gunsmith" going to get the brake correctly timed without use of shims or washer? Are they trained to just miracle the brake securely in the correct position?
The fact is, unless the threads on muzzle and brake just happen to have been cut perfectly--in relation to one another, and by different manufacturers--such that the brake threads right on and stops at just the right point of its rotation on the threads (which seems unlikely), then is it not inevitable that it will be necessary to time the brake, either with shims, a crush washer, or a lock nut? I guess the other alternative would be to mill some material off of the brake or barrel until the brake is correctly timed. That would be a complicated task, and would mar the finish. But that is why the world uses shims and crush washers, right?

if you're paying a gunsmith to time a brake, they should be turning the barrel shoulder on lathe

very common, not a complicated task at all.
way easier than cutting/reaming a chamber

[mmlook]

https://www.youtube.com/watch?v=lRyiMMX-k2g

[vintagearms]

I guess the other alternative would be to mill some material off of the brake or barrel until the brake is correctly timed. That would be a complicated task, and would mar the finish. But that is why the world uses shims and crush washers, right? Which is what a gunsmith would do...

No, won't mar the finish done right. Sinister Arms did my seamless AR15 and AR15barrels did one of my bolt actions. If anything, you'd only be recoating the muzzle break. No biggie.

You should be able to mount a muzzle break with crush, or shim without any help.

[Mute]

There are several brakes available now that do not need washers or shims to properly time. Spartan, Area 419, American Precision Arms. Take your pick. All good products.

[NapalmCheese]

I don't understand the assertion that no shim or washer is needed. How is a "qualified gunsmith" going to get the brake correctly timed without use of shims or washer? Are they trained to just miracle the brake securely in the correct position?
The fact is, unless the threads on muzzle and brake just happen to have been cut perfectly--in relation to one another, and by different manufacturers--such that the brake threads right on and stops at just the right point of its rotation on the threads (which seems unlikely), then is it not inevitable that it will be necessary to time the brake, either with shims, a crush washer, or a lock nut? I guess the other alternative would be to mill some material off of the brake or barrel until the brake is correctly timed. That would be a complicated task, and would mar the finish. But that is why the world uses shims and crush washers, right? Which is what a gunsmith would do...

Man, it sure sounds like you know what you're talking about, WE should be asking YOU the questions! You should spread your knowledge far and wide, I'd hate for some poor gunsmith to attempt to time a brake sans shims or a crush washer without your knowledge.

[ar15barrels]

Is there any benefit to using shims vs. crush washers to time a muzzle brake? I have a brake I need to install on my Remington 700 PCR. The brake was supplied with a crush washer. I suppose the first step should be to thread the brake on and see how it is timed without.

Do you ordinarily use a bit of thread locker on brakes? Like the blue Loctite?

Machining is best.
Shims are next.
Crush washer is worst.

The reason is that crush washers don't necessarily crush evenly.
Shims will at least be flat when tight since they do not collapse.

Most suppressor mounts come with strich warnings against use of a crush washer and usually include shims.
This is because the mount must remain straight/square to the bore so that bullets do not impact the muzzle device.

I recommend muzzle brakes and barrels be machined to time correctly without any shims or crush washers and I provide that service.