This system is a simple parts swap firing pin conversion. It replaces the factory breech plate and firing pin with a breech plate that has an offset rimfire firing pin. It's designed to work with our EABCO Custom Encore Accuracy Barrels® in 22 Long Rifle Match, 22 Winchester Magnum Rimfire, and .17 Hornady Magnum Rimfire. These barrels have a centered chamber and bore which means they require and offset firing pin to give rimfire ignition. This kit provides the offset firing pin.