A rim fire is a cartridge made from a case with no center primer. Instead it is totally enclosed and the priming material is sandwiched between the folds that make up the rim of the cartridge. The firing pin strikes the rim of the cartridge to ignite the powder. Example would be a .22 long rifle, .22 magnum, 17 hmr.
A center fire has a hole going through the
center of the head of the cartridge where a primer sits. The firing pin strikes this primer and sparks travel through this hole and ingite the powder. Examples would be .270 Win, 30-06, 45 ACP, 40 S&W.
Rimfire/centerfire
