BSF 6.5 Grendel Carbon Fiber AR-15 Barrel with a match-grade 416R stainless inner core sleeved in roll-wrapped carbon fiber. Provides rigidity, weight savings, and cooling. Outer carbon fiber sleeve and vent holes aid cooling. Barrel length 20 inches with a 1-8 twist for 6.5 Grendel ammunition. Compatible with AR-15 platform.