The hardening process of the SAG ensures it withstands wear from abrasive powder residue, prevents the formation of burrs when sliding against misaligned baffles and avoids embedding abrasive particles into its surface. Due to the significant variation in barrel bore diameters and straightness, the 0.002 inches undersize is considered optimal for fitting most barrels. The extended length of the SAG aids in aligning with the bore, eliminating the necessity for a tightly fitting gage. Fabricated from precision-ground, hardened steel, engineered to a tolerance of 0.002 inches below the nominal bore diameter for optimal performance and durability The external diameter is precisely machined and maintains a linear tolerance of +/-0.001 inches across its entire length Manufactured in the United States