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

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

SKU 789984
Brand SilencerCo
Model Number AC31
UPC 817272010213
This product is fulfilled by a PSA Partner and shipping times may vary.
These items are controlled by the U.S. Government and authorized for export only to the country of ultimate destination for use by the ultimate consignee or end-user(s) herein identified. They may not be resold, transferred, or otherwise disposed of, to any other country or to any person other than the authorized ultimate consignee or end-user(s), either in their original form or after being incorporated into other items, without first obtaining approval from the U.S. government or as otherwise authorized by U.S. law and regulations.

Product Details


  • Size: 9/16-24
  • Material: 17-4 Stainless Steel
  • Application: 40 S&W Handguns
  • For Use With: Omega K Series, Hybrid 46, Osprey and Octane Series Silencer


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 additional length between the threaded barrel and the silencer.


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