When metallic cased cartridges came about around the middle of the 19th century the powder was ignited through the rim of the cartridge being struck. This is how the term rimfire came about. Rimfire fell to the wayside with the advent of the center fire primer. Today rimfire is limited to smaller ammunition like 22 Long Rifle, 17 HMR, 22 Short, 22 Magnum, and 17 Mach 2. Here at True Shot Ammo we carry a great selection of rimfire ammo. We have all the major brands like Federal Ammunition, Browning, Armscor, Norma, Remington, and many more. So weather you need 22 LR for plinking, 22 mag for raccoon hunting, or 17 HMR for pest control. We have a brand and selection you need.