• *The discussion of the creation, fabrication, or modification of airgun moderators is prohibited. The discussion of any "adapters" used to convert an airgun moderator to a firearm silencer will result in immediate termination of the account.*

Silent Thunder Ordnance - Falx (First Impressions)

Just received my new Falx from Silent Thunder Ordnance (STO).
I currently own a 0DB moderator made for .30 caliber. It was recommended by AoA when I purchased my .25 caliber, Delta Wolf.
The 0DB weighs in at 7.4 Oz, 7.5 in length, and 1.570 in dia. The design of the 0DB is a metal can with an internal frame wrapped by felt or insulation,
My current experience with the 0DB is I lose about 3 MOA at 25 yds when I use it. The 0DB is relatively quiet compared to the Delta Wolf without a moderator.

I purchased the Falx for my FX Crown .22 caliber with a 600mm barrel after researching Airgun Nation and the STO site.
The Falx weighs in at 6.5 Oz, 6.5 in length, and 1.575 in dia. The design of the Falx is a metal can with a 3D-printed Nikola Tesla’s Gas Diode on the inside.
I have purchased an adaptor so the Falx will fit both the Crown and Delta Wolf.

I purchased the Falx instead of the Sarrissa mostly because of length.
It is hard to find data on why or how someone developed an acoustical dampener STOs Blog details how and why they designed their moderator. In my limited search, I found limited to no published R&D data from other companies on the web.

20221128_154924.jpg


20221128_155006.jpg


20221128_155031.jpg
 
Last edited:
Can anyone speak to the precision & accuracy experienced with the STO Falx? Have you noticed a positive or negative in this area? I have an FX M3 in .22 and can get MOA at 100 yards by just using the stock "can" the rifle came with. It's pretty quiet as it is but more quiet and more accurate would be better.
I had no change in accuracy at all.
 
Just received my new Falx from Silent Thunder Ordnance (STO).
I currently own a 0DB moderator made for .30 caliber. It was recommended by AoA when I purchased my .25 caliber, Delta Wolf.
The 0DB weighs in at 7.4 Oz, 7.5 in length, and 1.570 in dia. The design of the 0DB is a metal can with an internal frame wrapped by felt or insulation,
My current experience with the 0DB is I lose about 3 MOA at 25 yds when I use it. The 0DB is relatively quiet compared to the Delta Wolf without a moderator.

I purchased the Falx for my FX Crown .22 caliber with a 600mm barrel after researching Airgun Nation and the STO site.
The Falx weighs in at 6.5 Oz, 6.5 in length, and 1.575 in dia. The design of the Falx is a metal can with a 3D-printed Nikola Tesla’s Gas Diode on the inside.
I have purchased an adaptor so the Falx will fit both the Crown and Delta Wolf.

I purchased the Falx instead of the Sarrissa mostly because of length.
It is hard to find data on why or how someone developed an acoustical dampener STOs Blog details how and why they designed their moderator. In my limited search, I found limited to no published R&D data from other companies on the web.
What do you think of the Silent Thunder as far as sound suppression goes?
 
I've limited experience with moderators, STO, Huma and Silent Shot. I've 3 Falixs and 1 Sarissa. Judging is done by what my ear perceives while shooting. the STOs are quieter, lower frequency . The Falix is my go to moderator. The Sarissa is a fine moderator but I chose the Falix due to it's more moderate size.
 
I have a Vet .25. I'm using a Huggett Belita. It's 4.7" long, 3.4 oz, and 1.22" in diameter. It's the same diameter as the shroud, and looks like it's part of the gun. I'm shooting JSB's at 940 fps and all you hear is the hammer slap. This destroys the theory that you need a long, fat moderator to quiet the gun. It's also cheaper than a lot of the other ones.
i agree with your statement about the moderator size being the only way to quiet a gun. i’ve built one that’s also the same diameter as the notos shroud and it’s as quiet as bigger tube i have on it now.
 
I contacted STO about the one size fits all front end of their suppressors. They have flow choices but not caliber choices. And since I had an older Levitas in .22 I inquired about the change in design or no longer having a caliber choice. And now thinking about it, I don't think they offer anything over .30 cal. anyway. This is the response I got:
Our moderators are not as bore specific as other brands, we don't try to make the bores as tight as possible for performance gains since our diode technology is so much more effective than tighter bores and extremely tight bores often just leads to clipping and other problems. In some cases the opposite is true when it comes to changing the bore of the diodes themselves, changing the end plate bore, which is what determines the exit bore does have a very slight effect on performance. These can be specially requested when ordering or swapped easily later on but it's often not worth it.

Best regards,
STO

I will add that the first Levitas I tried, which did not have a flow selection back then, blew apart in my garage when I first tried it. They replaced it no charge and told me the design was changed to strengthen it. I have not as of yet tried the new sarrissa (high flow) on my .25 GK1, still waiting on a few things to give it a full power test.
 
I contacted STO about the one size fits all front end of their suppressors. They have flow choices but not caliber choices. And since I had an older Levitas in .22 I inquired about the change in design or no longer having a caliber choice. And now thinking about it, I don't think they offer anything over .30 cal. anyway. This is the response I got:
Our moderators are not as bore specific as other brands, we don't try to make the bores as tight as possible for performance gains since our diode technology is so much more effective than tighter bores and extremely tight bores often just leads to clipping and other problems. In some cases the opposite is true when it comes to changing the bore of the diodes themselves, changing the end plate bore, which is what determines the exit bore does have a very slight effect on performance. These can be specially requested when ordering or swapped easily later on but it's often not worth it.

Best regards,
STO

I will add that the first Levitas I tried, which did not have a flow selection back then, blew apart in my garage when I first tried it. They replaced it no charge and told me the design was changed to strengthen it. I have not as of yet tried the new sarrissa (high flow) on my .25 GK1, still waiting on a few things to give it a full power test.
So if I wanted to put one of the falx on a aea megalodon 50 caliber which one would I buy?
 
"So if I wanted to put one of the falx on a aea megalodon 50 caliber which one would I buy?"
You would very likely need to contact them as the site doesn't have information for a 50 caliber.

mike
 
I recently purchased a Standard Taipan Veteran from a member on this forum (smooth and great transaction). From all of the Veteran reviews that I read, folks were commenting on how quiet the Veteran is to shoot. I was a bit surprised at how loud my Taipan was as compared to the Leshiy 2 and immediately realized the sound level emanating from my Veteran was going to have to be mitigated. It was to time to find the right moderator to tame the noise.

A lot of folks are interested in and recommend the Donny FL stuff so I considered that as an option. I then read some things about Silent Thunder Ordnance specifically the Falx and the Sarissa. I didn't want to increase the overall length of my Veteran so decided to start with the Falx.

I emailed Silent Thunder Ordnance and they gave me feedback as to which flow factor was correct for my Vet. STO was helpful and communicated efficiently and answered all of my questions. I decided to purchase the Falx and a few days later I had it in my hands.

Overall it seems well made. Looking through the moderator I can see some of the 3D printed edges from the baffles, but nothing looks like it will deflect or interfere with the exit of a pellet. I'm not crazy about the shiny/glossy anodizing and would have preferred a type III matte anodizing (hardcoat), but it is what it is...

I'm a form follows function guy so enough about aesthetics, it was time to thread it on and test it. I installed the Donny FL threaded adapter (I'm impressed and it was machined perfectly - highly recommended) and then threaded the STO Falx onto the Vet. Fired a shot and began grinning. The Falx took a substantial amount of the bark from my Vet. I might end up getting the Sarissa to see exactly how quiet I can get the Vet.

It will have to wait until I can thoroughly test the Falx for any POA/POI shifting that could occur as a result of the moderator. So far I am really pleased and I believe this is a promising solution. Take care y'all!

-PJ
I didn't like the glossy finish either. I had US Cerakote make it a nice matte finish to match my gun. Very, very reasonable cost.