Manufactured in-house, these barrels are fully stress relieved, air-gauge tested, and 11 degree target crowned to ensure superior accuracy. Quality is imbued into our barrels from the start. We start with the best materials, either certified 4150 Mil-Spec steel or 416-R Stainless. From there, each barrel goes through a battery of tests at each operation until finished in Nitride and final inspected. All barrels are individually checked for headspace by precision custom hardened gauges. SPECS Barrel Material: 4150 CMV Barrel Type: Button Rifled Barrel Caliber: 5.56 NATO Barrel Twist: 1:8 Barrel Length: 7.5" or 14.5" Barrel Profile: Mfg: Faxon Firearms