The Mus II carries a dimensional envelope of 50x170mm, ~226 grams, with a semi-modular serviceable aluminum-tube design. The Mus II is the sucsessor to one of our early moderators, sharing the same size but with all our latest advancements in core design. The return of the Mus came out of a need for higher performance moderators to deal with the now more common very high airflows from slug guns and big bore rifles. It’s larger diameter of course allows for much more space to work with which can be an issue with large bores like .45 and .50 taking up a significant cross section of the core.

To really take advantage of the increased volume though took a considerable amount of testing as just using it as additional expansion volume has little effect on performance. We developed an entirely new acoustical testing system that is more precise and provides better data not only for peak amplitude but also total RMS and weighted sound levels for the whole duration. After dozens of experimental concepts were tested both iterating on previous designs and testing entirely new concepts we finally found some designs that really perform at these high power levels. To start these are available in only Extra High Flow cores which is designed for 160FPE+ with a shroud or 120FPE+ without. This correlates to Flow Factors in the 5000+ range.

The basic premise of the design is to use Nikola Tesla’s Gas Diode to reflex air back on itself and stop forward flow in the moderator. The moderator uses a three stage system. First the air is stripped off the pellet, reducing turbulence and improving accuracy. Second it is delayed via compound gas diodes. Finally a damping system muffles the sound. Most moderator designs focus on one of two capabilities, either sound wave damping or flow delaying, and this is copied the entire length of the moderator. Why though should the sound and flow at the back of the moderator be the same as at the front? It didn't make sense to us either, thus the design adapts along its length to maximize sound attenuation at a given flow level while minimizing size and weight.

The move to an anodized aluminum tube brings the advantages of serviceability/modularity. Mass varies by core, but is typically around 226 grams. Cores can be changed, and while this sounds small, from a development perspective it is a big deal. Previously, to test a new core design, an entirely new moderator had to be constructed. Now cores can be swapped, or even sections of the core as they too have been designed in a modular fashion. This speeds iteration and development substantially, and has lead to several key technological advances, with more to come. This design also sports a tapered bore, improving sound attenuation while reducing the likelihood of clipping. For you, the end line user, this means not only is the Mus is exceptionally quiet, it can be further improved with periodic upgrades as the technology advances.

Please note, while we try to keep core variants in stock for immediate shipment, some may be built to order, a process which takes two weeks. All designs are considered experimental.

This product is intended for AIRGUN USE ONLY. It is a violation of federal law to use this product in a manner inconsistent with its design intent. More information about the federal court ruling which clarified the legality of airgun moderators within the United States can be found HERE. Local restrictions may still apply. It is the responsibility of the buyer to ensure they are in compliance with all applicable laws.

This item will only be shipped within United States.