CVA Accura MR-X 45 Caliber Sniper Gray Cerakote Break Action In-Line Muzzleloader – 26in – The Accura MR-X is a shorter-barreled Accura muzzleloader (the MR stands for Mountain Rifle) and features a 26in Bergara Barrel. The MR-X is designed for hunters seeking a rifle that is both light to carry in the mountains and easy to maneuver in tight situations like thickets or tree stands yet still capable of reaching on out there when necessary.