What component of ammunition ignites the gunpowder?

The primer is the component of ammunition that ignites the gunpowder. It contains a small amount of explosive material that, when struck by the firing pin of a firearm, generates a spark. This spark ignites the gunpowder (or the powder charge), resulting in the rapid expansion of gases that propels the bullet down the barrel.

Understanding the function of the primer is crucial in the context of ammunition because it initiates the entire firing sequence. Each of the other components—the bullet, case, and powder charge—plays an important role, but without the primer's ignition, the powder charge could not burn and produce the necessary pressure to fire the bullet. Thus, the primer serves as the catalyst that triggers the entire process of discharging a firearm.