Ammo Primer Types

Ammo primers may be broken down to two main types:  both rimfire and centerfire versions are popular today. Rimfire denotes the type of priming agent used. Rimfire is so called because the firing pin strikes the cartridge base’s rim. Centerfire is operated by the firing pin striking the primer cap at the center of the base of the cartridge to ignite it. Here is a list of the Ammunition Primer types:

Rimfire Primers

Rimfire priming system is primarily used in small .22 caliber ammunition. Rimfire was popular before the advent of Centerfire priming and is still used in some Cowboy Action shooting. Rimfire ammunition is not reloaded.

Small vs Large Primers

There are two main types of primers in use today. Small Primers (.175”) are used for pistols calibers up to .357 Magnum (when using slower burning powder) and rifle calibers up to .223 while large primers generally apply to the larger calibers.  Here is a brief overview for reference: