Bolt action is a type of firearm action in which the weapon's bolt is operated manually by the opening and closing of the breech (barrel) with a small handle, most commonly placed on the right-hand side of the weapon (for right-handed users). As the handle is operated, the bolt is unlocked, the breech is opened, the spent cartridge case is withdrawn and ejected, the firing pin is cocked (this occurs either on the opening or closing of the bolt, depending on design), and finally a new round/cartridge (if available) is placed into the breech and the bolt closed. Bolt-action firearms are most often rifles, but there are some bolt-action shotguns and a few handguns as well. Examples of this system date as far back as the early 19th century, notably in the Dreyse needle gun. From the late 19th century, all the way through both World Wars, the bolt-action rifle was the standard infantry firearm for most of the world's militaries.