A.P.A developed the U.R.P. Adjustable Gas System. These aren't just randomly placed top ports. Every port is placed adjacent to the internal Bastard tooth where there is maximum pressure build-up. This makes the adjustable ports directionally effective. ALSO because of our self-timing Gen 2 system the brake is cant-able.
The unique tunable gas system combined with the trademark A.P.A ports work together to achieve a sight picture that does not move when the rifle is fired. There are 8 directional gas ports that can be tuned to counteract your U.R.P. (unique recoil profile).
There are 256 combinations to keep your sights on target. To calibrate the brake to your U.R.P., start testing with all the gas screws installed. Pay attention to the movement of your red dot, irons, or crosshairs, and begin removing the gas screws as the recoil requires.
When the gas screws are removed on the right side, the rifle will be shifted left. 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 you find your U.R.P. combination, Threadtite your screws into place.
This brake is meant for smaller barrels from AR-15's to hunting rifles. We recommend a barrel diameter of .600-.750 inches for this brake.