Semi-automatic shotguns are firearms that automatically cycle the action after each shot, allowing the shooter to fire multiple rounds without manually reloading after each shot. They use the energy from the fired shell to eject the spent cartridge and load a new one, making them faster to operate than pump-action shotguns. These shotguns are popular for various uses, including hunting and sport shooting. They typically hold a magazine that can contain several shells, and they come in various gauges, such as 12-gauge and 20-gauge, catering to different shooting preferences and needs.