Parts of a Cartridge and Caliber
Sometimes you will hear people on a rifle range say, "I'm out of bullets. Please get me some more bullets." Usually, these people don't know that they are asking for the wrong thing. Cartridges go into the chamber of a firearm, while bullets go out the muzzle. A bullet is only one part of a cartridge.
The ammunition used in a rifle or handgun is called a cartridge (or a metallic cartridge). There are two general types of cartridges available today: centerfire and rimfire.
Many years ago people used a larger number of different rimfire cartridges. The rimfire cartridge gets its name because the primer is in the rim. Rimfire cartridges cannot be reloaded. The most common rimfire cartridge used today is the .22 Long Rifle.
The centerfire cartridge is the most common type of metallic cartridge. The primer is in the (bottom) center of the ammunition. That's why this cartridge is called centerfire. Centerfire cases can be reloaded.
All cartridges—both rimfire and centerfire—have four main parts.
- Case: The case holds the primer, powder, and bullet.
- Primer: The primer compound explodes when struck by the firing pin and ignites the powder.
- Powder: The powder burns and creates gas to push the bullet through the bore and out the muzzle.
- Bullet: The bullet is the part of the cartridge that strikes the target.