 Also, a name change to ".450 Bushmaster" was approved.The .450 Bushmaster makes use of .452" bullets because of the lower impact velocities and energies would not adequately expand the heavier jacketed .458" bullets.The cartridge is chambered in bolt action rifles by Ruger,Savage, and Remington, AR-15 rifles, as well as an AR-15 pistol by Franklin Armory.