Criterion Barrels Heavy Hybrid LR-308 Barrel is a LR-308 rifle-length barrel built with a heavy hybrid profile. Caliber is 6.5 Creedmoor with a 22 inch length and a 1:8 twist. Made from stainless steel and finished in stainless. Designed for LR-308/AR-10 platform applications and optimized for heat absorption and harmonic consistency across high-rate-of-fire use.