Only the highest quality materials are used in META Barrels. META's automated machining and inspection processes ensure that nothing is missed throughout the manufacturing process. We employ rigorous in process inspection procedures both inside the machine via precision probes and outside the machine via skilled visual and live fire inspections. META Barrels are finished in Black Nitride and then engraved giving each barrel a stunning appearance. Combine this barrel with an APEX Bullpup Carbine Conversion Kit for a compact, precision shooting experience. The slim, ultra-lightweight 16 barrel design is a result of years of experience combined with around-the-clock R&D and testing. Product Features: PROUDLY MADE IN THE U.S.A., American Steel, Polygonal Rifled, Chrome Moly (CrMoV) Stress Relieved, Black Nitride Finish, 1:10 Right-Hand Twist Rate (6 Grooves), Button Rifled, High Precision / Tight Tolerance machining, Improved Lock up for increased reliability and accuracy, Proprietary thread with muzzle device and thread protector