Airgun Moderator Design, Performance, and Development - The Edgun Leshiy (part 10)

Catch the previous episode HERE.

So this project had a bit of an up-and-down. As mentioned before, this Leshiy is here by the grace of a very generous AGN user who goes by Custard. These cores are 3D printed, prototypes are done in ABS simply because it is easy to use and inexpensive. They also don't have to print perfectly, because they're just tests after all, and on all our designs we use a series of precision reamers to ensure the bores are precise and consistent. For a finished version to put in Custard's gun and ship back to him, we want a perfect print to do it in 20% carbon fiber reinforced nylon. This material is, in our humble opinion, one of the best possible options for silencer cores as it is very strong, light weight, solvent resistant, and impact resistant. It really is fantastic stuff. I should add that Glock's “magical” polymer frames are also made of nylon, it really does have great material properties.

So what happened and why am I bringing up all this? Well as you'll recall the previous test results were excellent. The small wrinkle was that there were a few little print flaws here and there which ought to be resolved before moving to nylon and printing the “final” core. So I made a couple little tweaks to fix the print issues, and confidently printed out a carbon-nylon core. Putting it in the gun I was expecting quietness..... which is not what I got. By ear I could tell it just wasn't right, way too loud. I didn't even need to meter it. I was more than slightly disgusted that just a few minor design tweaks had caused such a performance shift, I mean really. We would later meter this core, just for giggles, and discover it was averaging 155. NFG.

So this launched a frenzied, and not well documented, series of design tweaks and tests to try and figure out where the magic went (the original test core worked just fine, and still metered in the mid-teens) and how to stuff it back into the design. Yes, silencer design can be just this annoying and fickle. This process resulted in a dozen small tweaks, and ultimately the loss of a baffle. This circles nicely back around to the original test which, turns out, also performed better with just 3 baffles. Go figure. So, below, is the final series of confirmation tests on this project. And the rifle is already on its way back to Custard.

Factory Leshiy Configuration – 260.3
It is loud. We've been here. It is also inconsistent, unusually so, sometimes throwing numbers down in the hundreds other times throwing numbers over 300. In all my testing the highest number it ever threw was 364, the lowest 196. The average from the entirety of testing was 256.8, and the standard deviation 41. If you're wondering though why some test are a little high and others are a little low, this is why. That inconsistency means if you're only pulling 3 shot averages one shot low or high can really skew things. I feel this total average is very representative of the gun's capabilities in the factory configuration.

Final rev. core – 112.0
We lost a baffle here and also lost 3 points off the average of our previous best test. That is insignificant though because, even though this is an average of 8 samples, the standard deviation was 11. It is, to my ear anyway, a significant improvement in sound attenuation over the factory configuration so I'm happy with it. We didn't quite crack 100 (average) as I'd hoped, spending another two months trying to shave another 12 points off the average would be no fun so what is the point? There is also something else......

Extended Shroud/350mmBBL – 87.0
We wanted to test this configuration, not just confirm assembly/fit. For those unaware, there is a popular kit out there which takes minutes to install that gives the Leshiy a longer barrel, longer shroud, and more power. Turns out our new core works very well with it, as it comfortably cracks the 100 mark. Standard deviation was even 6.8. Being slightly less volume constrained obviously helped, but the other thing we did was take a special cut piece of foam that fits inside the spacer/shroud and around the barrel, and shoved that all the way to the back of the shroud. This way, as we learned testing on the Crown, sound would be less apt to reflect up and down the tube. And, thanks to my core design, the damper is essentially “built in” as it comes in contact with an angled rather than flat face.

So there it is, the Leshiy and new core are on their way back to Custard as we speak, along with our sincere thanks for letting us have a play with this system..... and thats enough of highly eccentric volume constrained systems for a while now. :P