3s/3ss .762-.830 Recoil Reducer 25 Cal Royal Arms.
SPECS: Machined steel blue, satin finish. 3" (7.6cm) long. Diameters: ACS/ACSS .750" (19mm); 3S/3SS .975" (24.76mm);
Big Book Catalog, Issue:71, Page:174
.30 Muzzle Brake Systems Ruger.
This Ruger® Muzzle Brake System includes a removable, radial-port muzzle brake that significantly reduces felt recoil. For times when the brake is not preferred, it may be replaced by the included dynamically-matched muzzle weight. Switching between the brake and the weight will not change the bullet's point of impact for a particular load. The included thread protector may be used if neither the brake nor the weight is desired. Fits .30 Caliber rifles with 1/2 x 24 muzzle threads. Note: product does not fit Ruger® Gunsite Scout Rifles.