Originally developed for the military, the OPS Muzzle Brake is the result of extensive research into muzzle gases and the effects of redirecting them for recoil reduction and accuracy enhancement. Excellent for big game as well as varmint cartridges ( The military uses it on 30 cal and 223).Recoil Reduction - The OPS Brake has a unique asymmetrical cupped primary baffle followed by a lateral secondary baffle. Recoil reduction of up to 70+% with virtually no “puff” back at the shooter… Varmint Hunters: No Dust Blow Ups!Accuracy Enhancement - The speed of sound changes with temperature so that within the OPS Brake, your bullet travels through an envelope of subsonic gas that enhances stability... Yes, that's pretty deep science. Rifles equipped with a preoperly installed OPS Muzzle Brake are extremely accurate and easy to shoot.The OPS Muzzle Brake comes in stainless finish only. It fits muzzle diameters from .530-.950 inch. Adds approx. 2”. 17-44 Caliber. Remember, this price includes our Precision Installation Process. See all of our muzzle brakes plus an explanation of our installation on our Muzzle Brake Home Page.