Stoger’s M3500 series of shotguns delivers quality and performance at an unbeatable price. These ultra-reliable semiautomatic shotguns are equipped with Stoger’s proven Inertia Driven System – a simple yet reliable action that differs from gas-operated semiautomatics. The Inertia Driven System is composed of just 3 moving parts and eliminates the need for gas cylinders, O-Rings, and other complicated parts. Instead of using gas expansion, the Inertia Driven System uses recoil to cycle shells. This allows the M3500 to handle a massive assortment of different loads from light 2 ¾” cartridges to 3 ½” magnum shells. The Inertia Driven System also keeps the action cleaner since all the gas and burnt powder are expelled through the barrel. Other features include a drilled and tapped receiver for installing Weaver 93 style optics bases, and an included shim kit allows the shotgun to be adjusted to a perfect fit. In addition, the M3500 comes standard with an integrated recoil reducer in the stock, and a high visibility fiber optic sight promotes greater accuracy in low light conditions. Features of the M3500: Inertia Driven System Drilled & Tapped Receiver for Weaver 93 Bases Shim Kit Included Integrated Recoil Reducer in Stock High Visibility Fiber Optic Sight Stoeger M3500 12ga 3-1/2" 28" Bbl Black 4+1 Semi-Auto Shotgun 36024