MPN: A02219


  • Precision Machined - Guaranteed thickness uniformity of ±0.0001” providing better muzzle device alignment
  • No Tolerance Stack-Ups - The single shim system eliminates tolerance stack-ups inherent with stacked-shim systems
  • Controlled Torque - Precise 20 degree indexing increments prevents the need for excessive installation torque
  • Simple To Use - Simply choose the correct size and install
  • Cost Effective - Will index about nine muzzle devices and reusable
  • Corrosion Resistant - Machined from high strength stainless steel bar with non-reflective oxide blasted finish
  • Impact Resistant - Can withstand hard front and side impacts


  • Material: 400 Series Stainless Steel
  • Finish: Oxide Blasted
  • Outer Diameter: 0.825"
  • Thickness: 0.060"-0.100"


  • 5/8"x24 threaded barrels


  • 18x Individually Marked Precision Armament Accu-Washer Shims (5/8-24)


Let's face it, there are some things you can get away with until you step up to a .30 caliber weapon. Not saying that a 5.56 is a lesser gun, but when you go bigger stresses do increase. That means every part of your .30 caliber rifle has to be up to the task. Heaver recoil means more abuse and vibration ringing through every part, even your muzzle device.

Tight Is Right

Do you really trust a low quality 5/8-24 crush washer to keep your muzzle device where it's supposed to be? Think about it, a 5/8-24 crush washer is designed to, well be crushed. How many times have you tried to back that muzzle brake off by hand after tightening it down on a crush washer? You know you have, I've done it myself just to check if it was tight. In the back of your mind, you just don't' trust that 5/8-24 crush washer, especially when it comes to your AR-10. However, you can believe in a Precision Armament 5/8-24 muzzle device alignment system.

It's So Simple

When you install a muzzle device, chances are good it won't crank down exactly true. Many muzzle devices have to be timed in order to perform. Instead of a crush washer that only should be good enough, what you need is a 5/8-24 muzzle device alignment system that you know is right. Precision Armament adopted the approach of just using the exact part you need to make it right. You simply choose one Precision Armament Accu-Washer, the one you need to do the job. Torque down that muzzle brake and forget about it. You shouldn't guess or hope, you have to know that it's right.

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