Many first time gun buyers find the topic of ammunition confusing. Here are some of the basics about centerfire cartridges.
Rifle and handgun ammunition, called cartridges (or rounds), fall into two main categories: centerfire or rimfire.
The terms "centerfire" and "rimfire" describe the type of ignition system within a particular cartridge.
A cartridge includes a metal casing which holds the primer, powder, and bullet.
The bullet is the projectile that shoots out of a gun, it is not the entire cartridge or round. Once the gun's firing pin hits the primer, this causes a tiny explosion which ignites the gunpower and propells the bullet out of the barrel.
In a centerfire cartridge, the primer is in the center of the cartridge.
Therefore, the firing pin in a centerfire gun is designed to strike the cartridge in the center, where the primer is.
Centerfire cartridge casings are made of metal that is thicker than that found in rimfire cartridges. Because of this, centerfire cartridges are comparitively more expensive than rimfire.
Centerfire ammunition is usually available in many variations within a particular caliber: different bullet weights/power levels and bullets themselves.
Another upside of centerfire cartridges is that they can be reloaded.
Because centerfire cartridges shoot larger bullets than rimfire, they produce more recoil.
Shotgun ammunition is called a shotshell. Shotgun ammo is typically broken down into three categories: birdshot, buckshot, and slugs.
A shotshell consists of a cylindrical casing filled with metallic pellets. The casing is typically made of paper or plastic. This tube sits on top of a brass base which holds the gun powder. Inside of the casing, above the powder, there is usually a wad of paper or plastic material which holds the shot in the upper end of the case.
Rifle and handgun ammunition is called a cartridge (or round). A cartridge includes a metal casing, powder, primer and bullet.