HUNTINGsmart! USA Knowledge Base
Module 01 - HUNTING BASICS
The ammo used for rifles and handguns is called a cartridge (or round). These are single projectiles that are available as either rimfire or centerfire.
Centerfire and Rimfire: What’s the Difference?
With rimfire ammo, the primer fills the space inside the bottom rim of a metal cartridge casing. The rim dents when the firing pin strikes it, which crushes the priming compound, causes an explosion and ignites the powder charge. The ignition of the powder charge then forces the bullet out of the barrel.
With centerfire ammunition, the primer is located at the center of the base in a separate cup. The firing pin strikes the primer, explodes the priming compound and ignites the powder charge. The ignition of the powder then pushes the ammunition out of the barrel.
Centerfire is the more popular option. The shell casing is stronger and won’t become as deformed after being fired, which means if it’s possible to do so, it can be re-fired (but first it must be polished, reshaped, re-measured and reloaded). Reloading is not an option with rimfire ammunition.