SilencerCo AC31 Osprey/Octane Piston 9/16x24 40 S&W Stainless Steel

The SilencerCo AC31 is an interchangeable suppressor piston designed for the Osprey and Octane series pistol suppressors from SilencerCo. This piston allows the shooter to configure their Osprey or Octane for use on .40 S&W host pistols equipped with a 9/16"-24 threaded barrel.

Pistons form the moving half of the Nielsen-style device that decouples the suppressor from the host firearm's barrel. When the slide cycles, the piston (rather than the entire suppressor) travels back and forth on the barrel, reducing the stress placed on the pistol's threads and locking lugs while maintaining a tight, repeatable seal at the muzzle. The AC31 is easily swapped out for other pistons in the Osprey/Octane family, allowing a single suppressor to be reconfigured across different host calibers and thread patterns.

This piston is machined from 17-4 stainless steel and then heat treated for maximum durability and wear resistance under the repeated cycling of semi-automatic pistol use. It carries a 9/16"-24 tpi thread pattern that threads directly onto the host barrel, and the stainless finish matches SilencerCo's premium suppressor hardware.

The AC31 is a .40 S&W piston intended exclusively for SilencerCo Osprey and Octane pistol suppressors. It is a component/accessory for a suppressor and is not a suppressor itself.