Silencerco 17-4 Stainless Steel Piston for .40 S&W Handguns, 9/16-24 - AC31

Our pistons were designed to be easily changed for different host firearms or calibers. Pistons are built with 17-4 stainless steel, then heat-treated for maximum durability. The piston is part of the Nielson device that moves and allows semi-automatic cycling for unlocking pistol barrels. Throw a Fixed Barrel Spacer on for fixed barrel applications. SilencerCo pistons have female threading that attaches to our SilencerCo threaded barrels. XL pistons are for firearms where the silencer requires