Ammunition

Ammunition

A round of ammunition consists of several key components:

  • Cartridge case: Holds the assembled round together. It expands upon firing to release the bullet or shot charge and seal the breech. Rimfire and centre-fire cartridges are typically made of brass, while shotgun cartridges are often made of polyethylene tube.
  • Primer: A small cup containing a detonating substance that ignites the propellant powder when struck by the firing pin. Rimfire cartridges have the primer built into the rim, while centre-fire cartridges have a separate primer.
  • Propellant powder: The substance that propels the bullet or shot charge. Black powder was the primary propellant before the 1880s, but smokeless powders are now the standard. Smokeless powders are more efficient and produce less smoke.
  • Bullet or shot charge: The projectile that is propelled by the propellant. Bullets are used in rifles and pistols, while shot charges are used in shotguns.

Reloading ammunition

While shotgun cartridges are typically purchased pre-loaded, many rifle and pistol shooters reload their own ammunition to save money or achieve specific performance characteristics. Reloading involves recovering spent cases, reassembling them with new components, and reloading them with fresh propellant and a new bullet.

Cartridge types

  • Rimmed cartridges: Have a rim around the base that helps with extraction.
  • Rimless cartridges: Have an extractor groove cut around the base for extraction.

Shotgun cartridges

Shotgun cartridges consist of a plastic tube, wadding, shot, and a primer. The wadding seals the gases and propels the shot. Both plastic and fibre wads are used, with plastic being more common due to its effectiveness. Lead shot is the standard, but alternatives like steel shot are available in some regions due to environmental concerns.

Bullet types

  • Lead bullets: Soft lead bullets were used in early muzzle-loading rifles. They are still used in some applications, but modern high-velocity rifles often use jacketed bullets to prevent lead build-up in the barrel.
  • Jacketed bullets: These bullets have a lead core surrounded by a metal jacket, which helps prevent lead build-up and improves accuracy.

Remember: The specific components and characteristics of ammunition can vary depending on the type of firearm and intended use. Understanding these components is essential for safe and effective shooting.