IMPORTANT NOTE: Holland’s Signature Series Muzzle Brakes require a Gunsmith Fit and adjustment to ensure proper dimensions, fit, and operation for your caliber and firearm. Brakes come standard with a .250 (1/4”) diameter caliber clearance, which must be increased if shooting a larger diameter bullet. If you are not trained and equipped to do this fitting, take your brake to a Qualified Gunsmith to be fitted. Installation Instructions are included with each brake.