What Is Ammunition?

Modern ammunition varies depending on the type of firearm. Rifles and handguns use a cartridge containing a single projectile (bullet). Shotguns use a shotshell containing either a single slug or a large number of small projectiles (shot). However, the basic components of cartridges and shotshells are very similar.

cartridge: Ammunition used in modern rifles and handguns; a case containing primer, gunpowder, and a bullet

shotshell: Ammunition used in modern shotguns; a case containing primer, gunpowder, wad, and a slug or shot

Basic Components of Ammunition

The basic components of ammunition are the case, primer, powder, and projectile(s). Shotshells have an additional component called wad.

Case: The container that holds all the other ammunition components together. It’s usually made of brass, steel, copper, paper, or plastic.

Primer: An explosive chemical compound that ignites the gunpowder when struck by a firing pin. Primer may be placed either in the rim of the case (rimfire) or in a cup in the center of the base of the case (centerfire).

Gunpowder: A chemical mixture that burns very rapidly and converts to an expanding gas when ignited. Modern smokeless powder will burn slowly when ignited in the open (outside of the case). Black powder is less stable and can be explosive when ignited in the open. Do not use black powder in modern firearms or smokeless powder in muzzleloading firearms.

Projectile: The object(s) expelled from the barrel. A bullet is a projectile fired through a rifle or handgun barrel. A slug is a projectile fired through a shotgun barrel. Shot is a group of pellets fired through a shotgun barrel.

Wad: A seal made of paper, felt, or plastic separating the powder from the slug or shot in a shotshell. The wad prevents gas from escaping through the shot and holds the shot together as it passes through the barrel