Primer:
A device for igniting the powder charge in a modern cartridge of centerfire ammunition. Cylindrical in shape, and inserted into a pocket built into the center of the base of a cartridge case in centerfire rifle, handgun, and shotgun ammunition. When struck in the center by a firing pin, the primer produces a spark or flame within the cartridge case, which ignites the powder charge and sends the projectile(s) (bullet or shot charge) downrange.