AR15 Crush Washer for 9MM & 5.56 Barrels

Yes. Most muzzle brakes need to be correctly timed in order to align the gas ports in the correct orientation. When installing a new brake it most likely won’t align perfectly. A crush washer allows you to exert additional force when installing the brake to align it perfectly, without putting stress on your barrel crown (which will negatively impact accuracy). Crush washers as the name suggests, compress when force is applied. It is better that the crush washer deforms then your barrel.

No! You should never use crush washers when using a suppressor/silencer. Crush washers don’t always compress uniformly when force is applied. This means, your muzzle device could become non-concentric (misaligned) with the barrel. And adding a suppressor could lead to baffle strikes.

When using a suppressor you must use suppressor shims when aligning a muzzle device.

The requirement is 15-20 ft-lbs of torque. Note: this is foot pounds. Do not confuse this with in-lbs (inch pounds)

We don’t recommend Loctite for muzzle installation. A better alternative is Rocksett Engineering adhesive. However, if your muzzle device is properly torqued, you shouldn’t need a thread locker unless you’re installing a suppressor attachment, in which case you should use a peel washer / suppressor shims and thread locker.

No. Most 9mm barrels will either be 1/2×28 or 1/2×36. Both of these thread pitches will use the same crush washer. This crush washer will also work with a 1/2×28 5.56 / .223 Remington AR-15 barrel.