Most bolt-action firearms use a rotating-bolt design, where the handle must first be rotated upward to unlock the bolt from the receiver, then pulled backward to open the breech and allowing any spent cartridge case to be extracted and ejected. This also cocks the striker within the bolt (either on opening or closing of the bolt depending on the gun design) and engages it against the sear. Upon the bolt being pushed back forward, a new cartridge (if available) is pushed out of the magazine and into the barrel chamber, and finally the breech is closed tight by the bolt head re-locking against the receiver.