Suppressor
The Ruger Mk4 is a forgiving host. The gun cycles reliably with any rimfire suppressor, regardless of backpressure level or weight, because it runs on a fixed barrel blowback design. The barrel doesn't move, so there's no need for a Nielsen device like a centerfire pistol would require, and the bolt is a single moving part with a high tolerance for varying backpressure.
The main consideration is opting for a low-backpressure can to prevent unburnt powder from blowing back through the ejection port into your face. As a bonus, lower backpressure also slows the cyclic rate slightly, making the pistol shoot a bit smoother. One caveat: the few cycling issues we've seen have involved low-backpressure suppressors paired with subsonic ammunition on the 3" barrel variant. This version was designed with higher backpressure suppressors in mind.
