The Benelli Montefeltro® Semi-Auto Shotgun is designed to be slim, trim, and lightweight. This gun is ideal for carrying long distances in fields while hunting pheasant or heavy brush while grouse hunting. The Montefeltro features Benelli's ultra-reliable Inertia Driven™ operating system.
When a gun is fired all of the fixed parts typically move reward. If the part is not fixed it initially stays put. The Benelli briefly holds its position as the rest of the gun moves backwards. The difference in motion compresses a very short inertia spring between the body bolt and bolt head. As the shot charge or slug leaves the barrel and rearward force on the gun diminishes. The spring vigorously rebounds throwing the bolt body reward with enough force to unlock the rotating bolt head, eject the spent shell and re-cock the hammer. The recoil spring then returns the bolt assembly forward, lifting and chambering the next shell, and then locks the rotating bolt head into the barrel extension.
This Inertia system is simple, consisting of just 3 main parts: the bolt body, an inertia spring, and a rotating bolt head.