Barrels are 6 groove, cut rifled, 1:10 Twist Right Hand, fully QC inspected, double honed (rough and finish) to produce the smoothest bore possible, with a Max Roughness Average (RA) of 12. Finished bore dimensions are held to +/- 0.0005" tolerance from nominal groove and bore dimensions but the dimensions are uniform to within 0.0002 for maximum consistency, accuracy and quality.SAAMI, Match Grade specification chambers, precision cut and finished to a maximum Roughness Average (RA) of 16.The pre hardened 416R stainless steel is stress relieved to an exacting recipe after rifling and final hardness is 38-42 Rockwell C before final barrel profile machining is completed.