Developed in cooperation with law enforcement agency assets, we have engineered this brake to deliver the ultimate in muzzle control performance for your carbine. Testing in full auto mode zero muzzle climb was the goal and this brake attains this goal.
This brake is designed for AR-15s in 223/5.56 with 1/2X28 TPI threaded muzzles. Will also fit other rifles in 223/5.56 with these same threads.
This brake indexes with a crush washer, which is supplied with the brake.
Outer Diameter: .870"
Ensure firearm is UNLOADED and SAFE before proceeding!
-¾”open ended wrench or adjustable crescent type wrench
-Anti-seize or other heavy grease
-Electrical tape (optional)
-Method to hold barrel or receiver
Remove any existing device from barrel. Note-many firearms may have factory installed muzzle devises pinned or welded on.
If you are not sure how to remove the device without damaging the firearm or muzzle threads, stop and consult a gunsmith.
Once the existing device has been removed, inspect and clean muzzle threads. Apply a small amount of anti-seize or heavy grease to the exposed muzzle threads. Place the enclosed crush washer on the muzzle so that the flared side of the washer faces toward the AT15 muzzle brake. Ensuring it is not cross threaded, carefully hands screw the AT15 muzzle brake onto the muzzle until it is hand tight on the crush washer.The supplied crush washer will allow the AT15 muzzle brake to be tightened approximately 1/2turn. If the brake is more than 180 degrees from 12 o'clock, remove the AT15 muzzle brake, flip the washer over and reassemble.
Secure the barrel or receiver from turning utilizing an approved method.
With a ¾” open ended or an adjustable wrench tighten the AT15 muzzle brake until the "ATRS" engraving is at Top Dead Center (12o'clock). Hint: If using an adjustable wrench, wrap a couple of layers of electrical tape to avoid marring the finish of the AT15 muzzle brake.
-In order to provide maximum effective muzzle control, the AT15 muzzle brake is required to be "timed". Optimal timing is achieved when the engraved “ATRS” is in the 12 o'clock position. When the AT15 muzzle brake has been tightened, the "ATRS" engraving will be pointing in line with the vertical axis of the firearm. Wrench flats will be on top and bottom when tightened.