|Available Calibers||.355||9mm||.38 Super||.400||40 S&W||.450||.45 ACP|
STI barrels are made from 416 rifle grade stainless steel billet forgings. The bore is gun drilled, button rifled, then air gauged to offer the most exacting size, and the most consistent barrel available. The rifling is 1 in 16 twist and has 6 lands and grooves. The barrels are vacuum heat treated and vacuumed tempered to 40Rc, then machined to exacting specifications. The barrels are short chambered to allow gunsmiths to cut the chamber to their application.