Surefire muzzle brake beveled shim

[n4p226r]

Anyone know what happens if you don't use it? I recently had 2 socom muzzle brakes installed and pinned on 14.5" barrels. The dealer said they install as per surefire's directions. Obviously the beveled spacer wasn't used or I wouldn't be here asking. I sat on Hold waiting for Surefire to pick up the phone for 10 minutes then 12 minutes then 45 minutes with no answer. Maybe they had a long weekend as this was Friday.

Thanks
Bill

[UWone77]

Anyone know what happens if you don't use it? I recently had 2 socom muzzle brakes installed and pinned on 14.5" barrels. The dealer said they install as per surefire's directions. Obviously the beveled spacer wasn't used or I wouldn't be here asking. I say on Hold waiting for Surefire to pick up the phone for 10 minutes then 12 minutes then 45 minutes with no answer. Maybe they had a long weekend as this was Friday.

Thanks
Bill

So you were able to time the brakes without any shims?

[n4p226r]

So you were able to time the brakes without any shims?

One shim was used on each

[n4p226r]

http://img.photobucket.com/albums/v2...pserz1rpve.jpg

http://img.photobucket.com/albums/v2...ps4v46bhjc.jpg


http://img.photobucket.com/albums/v2...psu1k7mlqt.jpg

http://img.photobucket.com/albums/v2...pshpibhrlq.jpg

[UWone77]

Ok, I get what you mean now.

I've got several installed this way, I've run into zero issues shooting them suppressed and unsuppressed.

[n4p226r]

Good to know. I couldn't think of any reason why it wouldn't be ok but I figure better check before blowing up a can I can only visit every few years

[gatordev]

The potential issue is that the main shim (with bevel) sets a uniformly square surface for the MD (and shims) to seat on when installed. Most 5.56 barrels have the shoulder below the threads, so the beveled spacer accounts for that. Personally I would be a little upset if they hadn't been installed (assuming you had a shouldered barrel), but it would make me feel a little better knowing UWone has shot suppressed without any issues.

[n4p226r]

What's the shoulder?

Being upset and cutting $260 in brakes that are pinned are two different things. I'm more worried that the second was needed.

[n4p226r]

http://img.photobucket.com/albums/v2...pspwuueqep.jpg

Here is one of my other barrels. What part of this does the spacer fix?

[Slippers]

The beveled shim is not always needed. Some barrels have a small radius from the threads to the shoulder. This prevents a muzzle device (or regular shims) from resting flat against the shoulder.

It's very easy to tell if you need it. Thread a muzzle device on with no shims until it stops, then hold the barrel up with a light behind it and see if there's a tiny gap between the muzzle device and barrel shoulder.

If there's a tiny gap and light is coming through, then you use the beveled washer with the bevel facing towards the rear of the rifle, followed by normal shims to time the muzzle device.

[n4p226r]

The beveled shim is not always needed. Some barrels have a small radius from the threads to the shoulder. This prevents a muzzle device (or regular shims) from resting flat against the shoulder.

It's very easy to tell if you need it. Thread a muzzle device on with no shims until it stops, then hold the barrel up with a light behind it and see if there's a tiny gap between the muzzle device and barrel shoulder.

If there's a tiny gap and light is coming through, then you use the beveled washer with the bevel facing towards the rear of the rifle, followed by normal shims to time the muzzle device.

And in one post it all makes sense now.

the shim takes care of a barrel threaded similar to this one? (pic taken from google images..sorry for unknown source)