This is a .44 caliber bullet in a .50 caliber sabot. For use in .50 caliber muzzleloaders. The new MZL Maximus high BC muzzleloader bullet was designed for use in in-line muzzleloaders and could possibly be the most accurate muzzleloader bullet ever made. These bullets were designed for that after 1-2" of penetration, 4 blades break off and radiate outward away from the main wound channel while the base continues through for even deeper penetration creating a massive amount of trauma. Mfg: Cutting Edge Bullets