SilencerCo AC25 Osprey/Octane Piston .5x28 9mm 1/2"-28 tpi Stainless Steel
This piston by Silencer Co. is made out of 17-4 stainless steel, and is used for 9mm caliber handguns. Made for the Osprey and the Octane, this piston features a 1/2"x28 thread pattern.