The Nosler Partition Spitzer Reloading Bullets feature crimp locks that add strength to help resist deformation under the pressure of heavy magnums and fully tapered copper-alloy jackets that rupture instantly at the thin mouths. A gradual thickening along the axes helps control expansion and curls the jackets uniformly outward at high and low velocities. Nosler Partition Spitzer Reloading Bullets, 115 - Reloading at Academy Sports