Looking for a rimfire cartridge with a centerfire attitude? Remington's got you covered with our complete line of Magnum Rimfire ammunition. Available in 17 HMR and 22 Win Mag Magnum Rimfire Ammunition is loaded for incredible shot-to-shot consistency flat trajectory and explosive expansion. Upgrading your rimfire rifle or handgun is as easy as shooting the right ammo. Think Magnum Rimfire.