Triple heat treated, highest quality, super match-grade barrels deliver maximum accuracy. Groove and bore tolerances held to an amazing .0002" by electro-discharge cathode machining (ECM). Unique, pre-cut design of the top lugs requires only minor fitting to achieve maximum lug engagement. Rifling is ultra-smooth, uniform, and precise. Smoother bore boosts velocity with all barrel lengths. Angled edge on the driving band increases gas seal for reduced fouling with all types of bullets, plus longer barrel life. Short chambered, requires reaming to achieve correct headspace. Mfg: Nowlin