For 5/8″x24 threaded barrels (majority of .308 barrels and Galil Ace 7.62x39mm). We found these AccuWasher shim kits to be very convenient to use. Although crush washers get the job done, a proper shim kit is the best way to mount a muzzle device. Outer diameter of .825″
Here is the description from Precision Armament:
- Precision Machined Mono-Shim: Provides exact muzzle device timing with external markings for easy identification.
- Unmatched Strength & Durability: Made from high-strength steel, equal to or stronger than barrel steel, ensuring failsafe strength.
- No Shear-Slip or Yielding: With its monolithic construction and significant thickness, AccuWasher shims resist deformation under heavy impact or bending loads.
- Maintains Accuracy & Safety: Eliminates alignment issues caused by traditional shims, preventing accuracy loss even under rough handling.
- Reliable for Suppressors & Muzzle Brakes: Provides the highest insurance against misalignment due to bumps, drops, or impacts.
- Fast, Intuitive Installation: External markings make it the easiest and most precise alignment system on the market.
Note: The AccuWasher Alignment System can be used with any brand muzzle device.





Robert Gager (verified owner) –
The washer are great they allow you to time your muzzlebrake easily. They are exactly what I needed and very easy to use without having to have a math degree to time it. Shipping was extremely fast. Thank you