Criterion Barrels Hybrid LR-308 Barrel 6.5 Creedmoor 20 Rifle-Length 1:8 Twist Nitride Black. This LR-308 compatible barrel features a Hybrid contour designed to balance weight and heat absorption with consistent harmonics. 20 inch rifle-length profile, 1:8 twist, finished in Nitride Black. Headspace should be checked for optimal performance and reliability.