Introducing Rev.3: The Biggest Moderator Upgrade in Years
Silent Thunder Ordnance
Silent Thunder Ordnance has been developing airgun moderators for years, and the aluminum tube architecture that underpins the current lineup has been in continuous refinement for over five years. That refinement has never really stopped. Customers who bought early units and customers who bought recently have been receiving progressively better moderators the whole time, we just weren't versioning them externally. That changes with rev.3.
What Versioning Means and Why It Matters
Major version bumps mark points of significant architectural incompatibility. The tube architecture is unchanged, however each core is made up of multiple parts, and it is those parts which are incompatible across revisions. A rev.2 diode section is not compatible with a rev.1 damping section; a whole core would have to be replaced. Minor version increments are more surgical and may allow individual components to be swapped. The tube itself, and the modularity it provides, remains constant across all revisions.
How Our Moderators Work: A Quick Primer
Our designs are built around two distinct technologies working in sequence: gas diodes and damping. Gas diodes, a valveless fluid control technology invented by Nikola Tesla, delay and redirect propellant air through geometry alone, with no moving parts. This is what separates our designs from conventional baffle stacks, and it's primarily responsible for reducing peak sound pressure. Damping material follows the diode stages and handles a different problem: absorbing the sound energy that persists after the peak.
Both matter, because peak and RMS tell different stories. Peak is the maximum instantaneous pressure of a shot event. RMS is total sound energy over the full duration. A moderator that hammers down the peak but leaves a long, elevated tail will still sound loud. The ear integrates that energy. Good suppression requires both.
What Changed in Rev.3
Rev.3 is the most substantial single upgrade to the moderator line since we moved to the aluminum tube architecture, and it is now live across the entire lineup: Pugio, Falx, Sarissa, Mus II, and Accipiter.
Previous revisions focused primarily on diode geometry, which benefited peak reduction primarily. Rev.3 is a ground-up overhaul of the damping system. The closed damping material surface area increased dramatically, and the open damping material was re-tuned from scratch for better flow resistivity and acoustic impedance. Critically, the damping section no longer functions as a largely independent third stage bolted onto the end of the diode stack; it has been redesigned to integrate tightly with the diode stages preceding it. The result is meaningful improvement in both peak suppression and total A-weighted RMS noise reduction across all flow ranges: standard through extra high.
Timing was partly driven by durability. As big bore airguns have become increasingly common at the upper end of our supported flow factor range, the damping section was seeing sustained stresses it was not originally designed for. Rev.3 addresses that directly. For shooters on the lower end of the flow range the durability improvement is largely academic, but the acoustic gains apply regardless.
The Quietest Airgun Shot We've Ever Measured
Data and traces for the majority of new moderator configurations are published on the blog, with historical data available for those who want to compare architectures over time. The standout result: a Crown .22 fired through the standard flow Accipiter Sarissa is the quietest airgun shot we have ever recorded across all testing. For a platform and configuration already known for exceptional performance, that result represents a meaningful step forward and reflects what a fully integrated diode and damping design can achieve.
We also moved to a new acoustic visualization in our test graphics that captures the full sound signature rather than just peak level, giving a clearer picture of what a shot actually sounds like from muzzle to silence.
For a deeper dive into how our moderators work, how to select the right variant for your rifle, and how to calculate your flow factor, the full configuration guide is available here.