Which component of a rimfire cartridge ignites the gunpowder?

The primer is a crucial component of a rimfire cartridge because it is responsible for igniting the gunpowder. In rimfire cartridges, the primer is located in the rim of the cartridge case. When the firing pin strikes the rim, it crushes the primer, causing a small explosion. This explosion produces hot gases and sparks that ignite the gunpowder within the cartridge.

Understanding the role of the primer is essential for comprehending how ammunition functions. It acts as the initial catalyst that sets off the chain reaction leading to the firing of the projectile. The other components, such as the projectile, case, and gunpowder itself, have their own functions, but none are responsible for igniting the gunpowder like the primer does. The projectile is what is launched from the firearm, the case holds all components together, and the gunpowder is the propellant but cannot ignite on its own without the primer.