View Full Version : AR-15 muzzle devices

September 15, 2004, 05:18 PM
Hey, looking to get my barrel turned and threaded for an A2 flashhider. I note that the A2 has no ports on the bottom, so it must be indexed correctly.

Anyone know how this works? I've seen references to crush washers and "peel" washers. Do I order the crush, then turn until properly indexed, crushing the washer to the proper thickness? Yet some things seem to say the peel washer is correct.


September 26, 2004, 10:37 PM
With a crush washer, you simply thread on the muzzle-mounted device until it's indexed the way you like it. It's easy. But, as with everything easy when it shouldn't be, the crush washers will allow the device to loosen relatively easily. Also, they can only be used once.

Peel washers are ok. Good idea, but when you actually use them, they are liable to loosen like the crush washers. I think it has something with the glue that holds them together vaporizing with repeated heat cycles.

Personally I'd just buy a bag of machined washers in .001" to .005" thicknesses, like a grab bag if you can find one. McMaster-Carr or Grainger has a large selection of washers. Hardened steel preferably. With this approach you can remove and remount the device (or leave it on permanently) and it'll stay tight relative to the crush/peel approaches.

September 26, 2004, 10:40 PM
By the way, I forgot to mention, if you get your AR's muzzle area cut, I heard that removing steel in this area will cause the bore to open up ever so slightly. (Thinning the barrel.)

Don't know if this makes a difference to you or not.

September 27, 2004, 01:11 AM
Ah, thanks for the reply. I'll look into the washers.

On the "thinning barrel" situation, I would think the flash hider, once installed, would keep the now thinned barrel in place, since all the metal is still there, just with threads inbetween.