John, this Mossberg 930 Tactical is a high performance gas operated auto-loading shotgun that handles the full range of 2 3/4" and 3" shotshells, including magnum field and low brass target loads.

This shotgun is gas operated sir. The Mossberg 930 Home Defense is an excellent alternative to the boring old pump-action shotguns that currently flood the market. Featuring an 18 1/2 inch barrel, the 930 Home Defense pairs a unique self-regulating gas system with a generous "5+1" shell capacity for a shotgun that was built for nothing more than to protect your home. Like other models in the 930 series, the 930 Home Defense is a 12-gauge shotgun with a three-inch chamber and a wealth of other practical features that make it worthy of more than a look or two.