The B.O.R. Lock MZ™ .50 Caliber Trophy Copper muzzleloader bullet’s easy-to-load, sabot-free design delivers excellent accuracy and impressive penetration. Federal’s innovative B.O.R. Lock MZ™ System has an expanding polymer base cup that grips the rifling with a tight seal for maximum velocity and superior accuracy. The Federal B.O.R. Lock MZ™ .50 Caliber muzzleloader bullet’s 270 grain copper-alloy projectile has a deep cavity surrounded by skives that work with the polymer tip to deliver consistent, devastating expansion. The Trophy Copper bullet’s high ballistic coefficient ensures flat trajectories with minimal wind drift. Fouling-cutting rings on the B.O.R. Lock MZ™ base scour powder residue from the bore as the bullet is rammed home during loading. The result is consistent seating and less need to clean between shots, plus the loading force required to ram home a B.O.R. Lock MZ™ .50 Caliber Trophy Copper bullet is about half that required for traditional sabots.