Nosler Partition® bullets give you accuracy, controlled expansion and weight retention. The fully tapered jacket of these 6mm, .243 diameter bullets ruptures instantly at the thin jacket mouth, yet the gradual thickening along the bullet's axis controls expansion and curls the jacket uniformly outward. A special lead alloy dual core construction provides superior mushrooming characteristics at virtually all impact velocities, and Nosler's integral partition supports the expanded mushroom and still retains the rear lead alloy core. A special crimp locks in the rear core section to provide strength to resist deformation under the pressure of heavy magnums. The enclosed rear core retains more than half the original bullet weight for deep penetration. Per 50.