Bartlein Barrels uses single point cut rifling because it is the least stressful rifling process. SPCR leaves the twist exact and the bore and groove more uniform. Barrels are pre-lapped before rifling and finish-lapped after rifling. With their extremely accurate rifling machines, Bartlein Barrels is capable of carrying the twist rate to the fourth decimal point. Bartlein Barrels are unmatched in barrel uniformity and bore finishes.