SilencerCo AC1346 Piston 45 ACP .578x28 XL Stainless Steel

The SilencerCo AC1346 Piston is an XL (extended-length) Nielsen device piston built for 45 ACP host pistols equipped with .578x28 threaded barrels. The piston is designed to be swapped between different host firearms or calibers, threading directly onto SilencerCo suppressor barrels to ensure proper cycling and alignment on handguns with longer or recessed threaded bores.

Machined from 17-4 stainless steel and then heat-treated for maximum durability, this piston is built to withstand the repeated recoil impulse of semi-automatic fire. The female threads attach to SilencerCo threaded barrels, allowing the user to change pistons to tune the Nielsen device for a specific host platform.

The XL (extended length) designation means this piston is intended for longer or recessed-thread barrels common on many 45 ACP pistols. Choosing the correct piston length maintains reliable lockup, proper alignment, and consistent cycling with the host firearm's breech.