U.S. flag

An official website of the United States government, Department of Justice.

Firearms Examiner Training


Home  |  Glossary  |  Resources  |  Help  |  Contact Us  |  Course Map


Analogy: A cartridge can be compared to an internal combustion engine.

Comparison of a cartridge to a gasoline engine:
Cartridge Gasoline engine
Projectile Piston
Cartridge case Cylinder and cylinder head
Primer Spark plug
Propellant Gasoline

Heat treatment: nonferrous alloys used for cartridge components work-harden as forming operations flex the metal. Two heat treat operations are commonly used in component manufacture:

Stress relief: a low-temperature operation that reduces stresses built in the material due to mild to moderate cold working. Parts are heated, but not to the point of glowing, then air dried.

Anneal: uses high temperatures to change the size of the metal grains, restoring softness and ductility lost in heavy cold working. Parts are heated enough to glow and then rapidly quenched in a coolant to preserve the change in grain structure.

Making any ammunition product requires that subassemblies (units formed of components) be made and incorporated into a larger assembly. Components for rifle and handgun ammunition are the propellant, the projectile, the cartridge case, and the primer. Shotshell ammunition adds a fifth component, the wad, which prevents mixing of the projectiles and the propellant.


Back Forward