SilencerCo AC24 Piston .578×28 | Osprey/Octane

The SilencerCo AC24 piston provides the female-threaded interface required for attaching Osprey and Octane pistons to compatible host firearms. Constructed from 17-4 stainless steel and heat-treated, the component is intended to withstand repeated service as part of a Nielsen-style device that enables semi-automatic cycling. It is offered with a .578×28 thread pattern and is listed for use with .45 ACP.

Common uses include range training and competition shooting where quick piston changes or caliber adaptation are required; it also supports multi-caliber suppressor setups when combined with the appropriate pistons and adapters.

Product Specifications

• The brand is Silencer Co.
• The model/fit is listed as Osprey/Octane.
• The thread pattern is .578×28 and the piston contains female threading to attach to threaded barrels.
• Caliber compatibility is shown as .45 ACP.
• The material is specified as 17-4 stainless steel and is heat-treated for durability.
• The finish is listed as Stainless.
• This item is a silencer piston designed to operate as part of a Nielsen-style device for semi-automatic cycling.
• The NFA thread pattern is recorded as .578×28.
• Threads are also indicated as .578-28 in the provided attributes.
• The product series is Piston .578×28.
• The listed length is 2.
• The listed height is 0.9.
• The listed width is 0.9.
• The listed weight is 0.1.
• The UPC is 817272010145.

The AC24 piston is a straightforward replacement or upgrade part when you need reliable, heat-treated 17-4 stainless construction and factory-compatible threading for SilencerCo Osprey and Octane systems. Its interchangeable design supports multi-caliber use when combined with the correct pistons and accessories, making it a practical choice for shooters who prioritize modularity and serviceability.