1911 Ramped barrel with Para/Clark barrel with bushing link and pin. Stainless Steel 416 barrels are machined from solid 416 stainless bar stock, tolerances held to +/- .001″ in critical areas, finish heat treated to 40-42 HRC and cut broach rifled. Barrels feature left hand 1 in 16″ twist with 6 lands and grooves. Barrel kits are drop in and usually require little to no fitting. Threaded barrels thread pitch are .578×28 for the 45 ACP.