A rifle cartridge is a type of ammunition designed for use in a rifle. It typically consists of a bullet, gunpowder, and a casing that holds everything together. When the rifle's trigger is pulled, the firing pin strikes the primer at the base of the cartridge, igniting the gunpowder and propelling the bullet out of the barrel. Rifle cartridges come in various calibers, which refer to the diameter of the bullet. Common calibers include .223 Remington and .308 Winchester. Each caliber is designed for specific purposes, such as hunting or target shooting, and can vary in power and accuracy.