CVA™ Accura MR-X - .50 Cal 26" Barrel Threaded - Stainless Steel Barrel Black Stock 1:28 Twist - PR3241SMThe . 50 Caliber CVA Accura MR X Muzzleloader is an upgraded version of the Accura MR. The Accura MR X muzzleloader carries over most of the features from the previous model with some serious upgrades to the stock, fit and finish, and long range terminal performance. The . 50 Caliber Accura MR X Muzzleloader is the ultimate rifle for hunters wanting a compact design with increased BC bullets and velocities. This gun is right at home chasing whitetails