Lantac barrels are manufactured to the highest level of accuracy during the machining process. Each barrel is chambered and head spaced to a master bolt face with barrel extension individually matched to each barrel too. Chambers are carefully polished after reaming. Our barrel blanks are precision gun drilled, double reamed, precision honed and then rifled with a progressive button system utilizing 6 groove rifling that has been proven to produce the highest level of shooting accuracy. Barrels are also air gauged with a bore concentrically tolerance between .00005''to .0001'' and Cryogenically treated. All muzzles are precision 11 target crowned. Specifications for LANTAC Raven .300 BLK Barrel: Manufacturer: LANTAC Color: Black Finish: Black Caliber: .300 AAC Blackout Features of LANTAC Raven .300 BLK Barrel: Certified 416R Stainless Steel Highest 'Barrel Quality' steel available cryogenically treated and double stress relieved. Ultra precise 6 groove 2 pass button process proven to perform to the highest levels of accuracy. Head-spaced to master bolt face. Extended M4 feed ramps YAG Fiber laser engraved logos and nomenclature. Fine bead blasted finish before final surface treatment Proprietary black surface conversion finish 5/8x24 muzzle threads with precision 11 target crown Lantac USA barrel contour Package Contents: LANTAC Raven .300 BLK Barrel