The SilencerCo AC28 Osprey/Octane Piston in 16M x 1 LH for 45 ACP delivers a rugged, easily swappable solution built for durable performance in the field or on the range. Crafted from 17-4 stainless steel and heat-treated for maximum durability, these pistons are designed to be changed quickly to adapt to different host firearms or calibers, with female threading that securely attaches to SilencerCo threaded barrels. As part of the Nielsen device, the piston moves to facilitate semi-automatic cycling for unlocking pistol barrels, while a Fixed Barrel Spacer option accommodates fixed-barrel applications, expanding the pistons versatility across setups. The XL variant provides additional length where the silencer requires extra distance between the threaded barrel and the device, ensuring reliable operation in a variety of configurations. Finished in black stainless steel, this SilencerCo piston is purpose-built for the Osprey and Octane line, offering a robust, precision-made component that supports smooth cycling, dependable repeatability, and straightforward compatibility with threaded SilencerCo barrels in 45 ACP platforms.