OSS RAD PISTON .578x28 Thread Adapter for Suppressors

The OSS RAD piston .578x28 thread adapter is a precision suppressor component built for shooters running Operators Suppressors suppressors on reciprocating or fixed-barrel platforms. This piston threads directly onto your firearm's muzzle at the .578x28 pitch and accepts either a Piston Spring for recoil-operated barrels or a Fixed Barrel Spacer for non-reciprocating setups, giving you flexibility across multiple rifle configurations. Built from 17-4 stainless steel with heat treatment and black nitride finish, it's engineered to withstand repeated cycling and corrosive environments without degradation.

What sets the RAD piston apart is its cross-platform compatibility. You can swap it between RAD 9 and RAD 45 suppressors, and it shares geometry with SilencerCo and Rugged pistons, so if you're already running one of those ecosystems, this adapter works seamlessly in that network. The wrench flats machined into the piston body let you tighten it securely to your barrel extension without relying on hand-tight fitment alone—a practical detail that matters when you're running a suppressor through repeated fire cycles at the range or in the field.

If you're building a suppressor-ready rifle or adding another platform to an existing RAD can, the OSS RAD piston is the interface that keeps everything locked down and running right. It's a straightforward, well-made component from a manufacturer focused on suppressor reliability and modularity.

Key Features

• 17-4 stainless steel construction with heat treatment for durability
• Black nitride finish for corrosion and wear resistance
• Wrench flats for secure, torqued attachment to your barrel
• Interchangeable with RAD 9 and RAD 45 suppressors
• Compatible geometry with SilencerCo and Rugged pistons
• .578x28 thread pitch
• Works with either Piston Springs (reciprocating barrels) or Fixed Barrel Spacers (fixed barrels)

Specifications

Frequently Asked Questions

Can I use this piston on both reciprocating and fixed-barrel rifles?

Yes. Pair it with a Piston Spring if your rifle's barrel cycles with the bolt, or use a Fixed Barrel Spacer if your barrel is rigidly mounted. You'll need to source the spring or spacer separately based on your setup.

Will this OSS RAD piston work with SilencerCo or Rugged suppressors?

The piston shares compatible geometry with SilencerCo and Rugged pistons, so you can use it across those platforms if you own multiple suppressor cans.

What thread pitch do I need for my rifle?

This adapter is .578x28. Make sure your rifle's muzzle device or barrel is threaded at .578x28 before ordering. If you need a different pitch, you'll want to confirm the thread size with your barrel manufacturer or gunsmith.