A semi-automatic firearm (or “semiauto), also known as a “self-loading” or “autoloading” firearm, refers to the mechanism employed to load cartridges into the chamber for firing as well as expending the spent case. A semiauto firearm is designed to fire one round (bullet) with each pull of the trigger, automatically eject the spent cartridge case and chamber a new round from the magazine for the next shot. The operator then must pull the trigger again to fire the firearm. Typically, the mechanism takes advantage of the firearm’s energy created when a cartridge is shot – there is excess energy that is used to enable the autoloading mechanism (e.g., push the bolt or slide backwards). Semiauto firearms are available as handguns, shotguns and rifles, along with other actions (e.g., bolt action, pump action, etc.)