The Maple Ridge Armoury V1 Match Nitride AR-15 barrel is precision CNC machined in Canada from premium, GBQ 4140 CMV steel blanks. These button rifled blanks are honed, lapped, and stress relieved. Honing controls bore dimensions down to a tolerance of 0.0001″ and lapping is added quality assurance to ensure a concentric and uniform bore. The blanks are air gauge tested during final inspection to ensure the most exacting tolerances. More information about the features and benefits of our barrels can be found in the product description tab below.