Our V.P.R. (Variable Port Recoil-Reduction Muzzle Brake) is designed with varying degree port angles to redirect the gases out and up to reduce felt recoil as well as reduce the flash signature. We 5 axis CNC machine these from 303 stainless steel to get the proper port angles. The port angles start with a 15 degree back angle and decrease as the gases disapate moving forward. This provides the shooter with a smooth feeling recoil reduction.