SilencerCo AC626 Piston | 17-4 Stainless Steel | 13.5×1 LHM XL

The SilencerCo AC626 piston is a heat-treated 17-4 stainless steel replacement piston designed to provide the female threaded interface for compatible SilencerCo suppressors. It uses a Nielsen-style design that enables semi-automatic cycling on compatible pistols while also allowing multi-caliber use through interchangeable pistons. The AC626 is intended for range use and competition where quick piston swaps or caliber conversions are required.

Product Specifications

• The piston is constructed from 17-4 stainless steel and heat treated for durability.
• The finish is listed as Stainless.
• The thread pattern is 13.5×1 LHM XL.
• The NFA thread pattern is 13.5x1mm LH.
• The product type is listed as Multi-Caliber.
• The model name is Piston (AC626).
• Compatible suppressor families include Octane Series, Osprey Series, Omega K Series, Hybrid 46.
• This piston is part of the Nielsen device and enables semi-automatic cycling when used with compatible hosts, listed as part of the Nielsen device.
• The piston features female threading to attach to SilencerCo threaded barrels, listed as female threading.
• The size is listed as XL.
• The product subcategory is Suppressor Accessories.
• The listed weight is 0.1.
• The UPC is 817272011623.

Purpose-built for users who need a durable, serviceable piston for multi-caliber suppressor setups, the AC626 delivers a straightforward interface and proven materials. Its heat-treated 17-4 stainless construction and compatibility with multiple SilencerCo families make it a practical choice for range training and competition applications where reliable piston swaps and caliber flexibility matter.