What mechanism allows the semi-automatic shotgun to reload automatically?

A semi-automatic shotgun uses the gas force generated from the spent shell to automatically cycle the action of the firearm. When a shell is fired, gas from the ignited gunpowder is redirected through a port in the barrel and used to push a piston or operate a mechanism that ejects the spent shell casing, chambers a new round, and readies the shotgun for the next shot. This process allows the shotgun to reload without any additional effort from the shooter, enabling faster follow-up shots compared to manually operated shotguns.

Understanding how the gas operation works is crucial for ensuring proper maintenance and reliable functioning of the firearm.