Gen 4 Muzzle Brake Installation and Tuning

Installation Instructions

1. Check that the firearm is unloaded and the chamber is empty.
2. Remove the existing muzzle device if applicable.
3. Clean muzzle threads with quality cleaner.
4. With the nut screwed all the way on the brake (not separately), thread the entire unit threads onto the muzzle until the nut contacts the shoulder of the barrel.
5. Back off the muzzle brake until the ports are indexed at 3 and 9 o’clock or until the line on the front of the brake is level.
6. Tighten the nut with a crescent wrench slightly beyond hand tight.
7. Overtightening could result in damage to our products or your barrel.
8. If your shoulder is not square or of sufficient diameter for your barrel you may require purple or blue Loctite on your barrel threads only to hold the brake in place.
9. Proceed to tune the U.R.P. gas ports with the instructions below.
10. Now that you have installed and tuned the muzzle brake for sight picture proceed to zero your rifle.

Utilizing the U.R.P. Tunable Gas System

The unique tunable gas system combined with the trademark APA ports work together to achieve a sight picture that is trackable when the rifle is fired. Once the following tuning procedure is complete you can then zero your rifle.

There are 8 to 6 directional gas ports that can be tuned to counteract your rifle’s U.R.P. (unique recoil profile). There are many combinations to keep your sights on target.

1. To calibrate the brake to your personal U.R.P., start testing with all the gas screws installed. We suggest choosing a shooting position that you find difficult to retain a sight picture. Example: Shooting off a fence post with a Game Changer Bag. 
2. Fire at least one round paying close attention to the movement of your reticle. Don’t worry about hitting the target, that will come later in step 5. 
3. If the sight picture is too high begin removing the 1 to 2 gas screws from the muzzle end of the brake. If the sight picture is too low add 1 to 2 gas screws back.*
4. Repeat steps 2 and 3 until the desired sight picture has been achieved 
5. Now zero your rifle.

When the gas screws are removed on the right side, the rifle will be shifted left under recoil. For the opposite effect, simply remove the screws on the left. The gas holes closer to the nut have a more dramatic effect and the ports closer to the brake crown have a lesser effect.

*When reinstalling screws be sure not to cross thread. You may need to first rotate the screw counterclockwise allowing it to fall into place. Then turn the screw clockwise to tighten with no resistance until it bottoms out.

No Threadtite is required for Gen 4 brakes.