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Moderator designs

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Redtick12

Redtick12

Member
Aug 21, 2021
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Klamath Falls, Oregon, United States
There seem to be two different approaches to moderators. One being a chamber filled with some sound dampening material like felt. The other being a chamber with baffles of some sort that strip the air and redirect it. I read about the possible accuracy affects of air turbulence around the pellet as it leaves the barrel. Is this a thing? Is one of the methods above more or less effective at reducing that turbulence and therefore improving accuracy? What if the two methods were combined, some cool shaped baffles to strip the air (maybe reducing the turbulence?) then some sound absorbing material. Has this been done? How effective is using the barrel shroud as an expansion chamber to suppress the sound? Way back with AirForce airguns I read about people drilling small holes in their shrouds to vent it making the shroud more effective. Did this work, did it make a difference?
 
This is from personally experience. I've been lucky enough to try a lot of different moderators, either buying them or using one from a friend. I've tried baffles and no baffles. I've tried the big "soup can" moderators and the tiny slim ones. All were used on a Taipan .22 shooting JSB 15.9 at 966 fps. The smallest one I used is the Huggett Atom. The biggest was the Donny Ronin. The Atom was the clear winner for being quiet. It has no baffles and is the same diameter size as the Taipan shroud, so it is not noticeable unless you look close. It's 3.5" long, 1.22" in diameter and weighs 2.5 ounces. I like it because I don't like the "soup can" look at the end of the barrel. YMMV
Here's a picture of the Atom on the Taipan

IMG_2071.jpg


IMG_2071.jpg
 
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www.silentthunderordnance.com

Shroud Damper — Silent Thunder Ordnance

This is one of those undervalued little accessories that sometimes makes a small difference, but sometimes makes a big one. It is a sound damping system designed to fit inside the reflex volume (shroud) of a rifle, which improves the overall sound attenuation with or without a moderator. The most
www.silentthunderordnance.com www.silentthunderordnance.com

this person says that the shroud vent holes actually make things louder. He has a blog where he tests a bunch of moderators and developed his own. I own a sarissa. It is big, but it is very quiet.
 
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On one hand, I suppose that suppressor contents could effect the accuracy, depending on design.
On the other hand, I did a hand made baffle system for my Ataman, BP17 (no suppressor photos). It comes with a "can"...full of air. I hear that some have a single wall inside, mine came empty.

I tried several somewhat...normal, methods of quieting the sound. Nothing worked very well.
Then a brainstorm... How about moving baffle walls ? Let the air pressure, fill and enlarge each chamber (three) to lessen the load on the next chamber.
I went to the local hobby shop. Bought some all-thread, three RC spur gears, a bunch of nuts, then came home and dug up a hand full of ball point pen springs.
Long story short, if ANY baffle system was going to effect the point of impact, this would. BUT...guess what, it's not only fairly quiet, it also had NO effect on the pellet point of impact.

And like I was told with my Daystate, Renegade and Pulsar, the original equipment baffles effect the point of impact on these guns.
Well...sorry to disagree, the original, un-modified baffles with a shortened original spring (so the baffles move easily), also...does not effect the point of impact, on either gun.

Granted, on any of the three noted guns have I shot to 100 yrds., but in my shorter range, no effect on where the pellet goes.

Mike
 
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Accuracy issues with moderators.
I’m always wonder how well these moderators are mounted in true alignment with the barrel.

Considering some of the designs they have 2-3 threaded bushings, from the barrel nut, slide on shroud, and the moderator threaded into the shroud. Bunch of orings trying to keep stuff straight.

If u measure the exit holes on some of them, for .22 cal they will be .3”or more.
 
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ddnzf said:
www.silentthunderordnance.com

Shroud Damper — Silent Thunder Ordnance

This is one of those undervalued little accessories that sometimes makes a small difference, but sometimes makes a big one. It is a sound damping system designed to fit inside the reflex volume (shroud) of a rifle, which improves the overall sound attenuation with or without a moderator. The most
www.silentthunderordnance.com www.silentthunderordnance.com

this person says that the shroud vent holes actually make things louder. He has a blog where he tests a bunch of moderators and developed his own. I own a sarissa. It is big, but it is very quiet.
Click to expand...
Interesting....good info
 
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One of the most effective screw on moderators made was the old standby Weihrauch OEM.

Inside is a proven recipe, shared by most fairly effective moderators:

3 chambers: setup Large-Small-Large, separated by 2 stainless washers, surrounded with a layer of felt and haircurler stuff to keep it in place. That's it. Works better than most and it's feather light and looks clean and trim.

I had a Huggett of similar size and it wasn't any more effective, and barely as quiet, if at all.

The DonnyFL stuff is heavy, overly complicated and doesn't offer as much sound suppression to my ears. All the fancy stuff on the inside just takes up space that could be taken advantage of for extra internal volume.

Sometimes simple just works, and in the case of airgun silencers, I think that rings very true. That's been my findings anyway.

The main thing is the silencer just has to big enough. More internal volume is always better and I think we can all agree on that at least.

And concerning affecting accuracy, most moderators these days are fitted with adapters or loose tolerance threads, and mounted onto shrouds supported by squishy orings. So all the precise stuff in the universe can be inside, and none of it will matter if it's not setup concentric to the bore and the holes square to the muzzle. It's only as good as how good it fits, and most just fit "okay".

My two cents..
 
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There's quite a few other moderator designs.

One of the best moderator designs (for sound dampening, not accuracy) is the "wipe" model. This is where there is an essentially solid rubber barrier in the moderator, and you shoot through it. Usually it is designed so that it can somewhat "heal" after each shots. Often these "wipe" models are non-functional after about four shots.

Here is a demonstration of a "wipe" silencer:

Other designs include moderators with spirals and moderators with "cloudy" tubes of multiple lengths. These often have to be 3d-printed. The idea with these designs is to have two (or more) distinct shock waves of air, to aid in diminishing the report, i.e. spread out the shockwave as much as possible.
 
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i dont think a moderator is a good air stripper .. the air is in there its doing somethin, even if its not bad its not really stripped lol .. i did buy a mac1 'stripper', not a moderator, for my mrod25 strictly because it looks bad*** but i was surprised it actually tightened up shots .. all that said, i like the precision machining on donny stuff and they work .. i certainly dont want some cheap garbage on the end of my gun ...
 
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Ca_Varminter said:
Unless you have an Air-Stripper integrated into the Mod/Shroud design!
New-Stripper2.jpg


I did machine up some K-baffles for my shroud... So the combination of the baffles and being volumetric
She is quiet...
k-baffle3.jpg
Click to expand...
Nice work. Do your baffles have the window in the side of the skirt and the capture area on the top which redirects into that area. Like this?

k-baf.jpg
 
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OldSpook said:
Nice work. Do your baffles have the window in the side of the skirt and the capture area on the top which redirects into that area. Like this?

View attachment 279547
Click to expand...
No... Just a simple conical skirt with a flat base with symmetrical holes drilled around the perimeter of the bore for except the first one.
The first one has a conical protrusion with 11° taper...for more of a stripping effect.
k-baffle4.jpg
 
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