Sometimes on a rifle range you will hear people say, “I’m out of bullets. I need more ammo. Can somebody please get me some more bullets?” At a recent Hunter Safety class I was assisting with one of the young students asked that very question. You should have seen the confused look on his face when I went to my truck and brought him back a box of 100-grain, .257 caliber Nosler Ballistic Tip bullets I’d just purchased as a reloading component.

When people say, “I’m out of bullets,” what they mean is, I am out of cartridges. They don’t realize they are asking for the wrong thing. Simply stated, a bullet is just one of the four main components of a cartridge.

The ammunition used in a rifle or handgun is called a cartridge, and there are two general types of cartridges used by rifle and pistol shooters available today — centerfire and rimfire. The basic difference is where the primer is located. A rimfire cartridge is so named because the primer is located in the rim of the metallic case. Rimfire cartridges cannot be reloaded. And while many decades ago there were a large number of different rimfire cartridges commonly used, today the most common rimfire cartridge is the .22 Long Rifle (along with the .22 Short and .22 Long.)

The centerfire cartridge is the most common type of cartridge. The primer is located in the center of the bottom of the cartridge case — hence the name, centerfire. Centerfire cases can be reloaded.

Both rimfire and centerfire cartridges have four main parts. They are:

1) Case

The metallic case holds the primer, powder, and bullet. Cases are sized to fit precisely into the chamber of a given caliber firearm.

2) Primer

The primer consists of the priming compound, which in the case of a centerfire cartridge is located in small metal cup that’s seated in a hole in the bottom of a centerfire cartridge. In the case of a rimfire cartridge, the priming compound is located in the rim of the metallic case. In both cases this priming compound explodes when struck by the firing pin. This is what ignites the powder.

3) Powder

Once ignited by the primer, the powder burns rapidly, creating a gas that expands rapidly. The resulting pressure from this expanding gas pushes the bullet down the barrel and out the firearm’s muzzle.

4) Bullet

The bullet is the component that flies out the barrel and downrange, hopefully striking the target where you’ve aimed.

So, next time a buddy asks for more “bullets,” you’ll know what he really means. He needs more cartridges.