• The AGN App is ready! Search "Airgun Nation" in your App store. To compliment this new tech we've assigned the "Threads" Feed & "Dark" Mode. To revert back click HERE.

Evanix rex shroud modification

Jump to latest Follow Reply
MrP

MrP

Member
Apr 29, 2020
1,429
622
New Lebanon, NY, USA
(I posted this same message at GTA - not sure which site would have more evanix users who might be interested in this. I would be happy to share the stl files though there is nothing at all complicated to these simple parts).

I’ve been enjoying my .357 evanix Rex, which is powerful and quiet compared to my previous foray into .357 airguns.

It still puts a hurt on my ears and I don’t like wearing protection if I can safely avoid it.

The Rex has a really large shroud with lots of volume but it is purely cosmetic and non-functional, and this pisses me off more than it should. I think it is a missed opportunity. I have a can I can put on the end but there are a few reasons I don’t like that solution either so I am going to try making the shroud into something functional, allowing air to expand back into. 3d printer makes it possible!

Problems to fix:
1) front bushing isn’t vented
2) shroud has a bunch of large holes drilled in it for looks rendering it useless
3) end cap isn’t contoured to shunt air backwards

So I am printing a vented barrel bushing, a long tube-like insert to nest in the bottom part of the shroud and block the holes, and a baffle for the small chamber at the end which I hope will strip and force air backwards.

The baffle I think can be improved - I will likely redesign that part.

Two pics attached, one of the parts in tinker cad and another of the shroud. Right now I’m just printing prototypes to test for a fit. I may try to incorporate some O-ring grooves to get better seals against the shroud in future iterations

My hope is to get more of a muffled report, not aiming for anything other than “shooter friendly”. I am very curious to see how much change there is and to what degree just allowing air to flow back into a shroud will quiet things down.

8418E89E-DCC8-4F9E-B53B-8D42A24AE138.jpeg


FFC74749-08BE-49A7-902D-ADCE271C5BB2.jpeg
 
  • Like
Reactions: Sean Riley, Hoffman9517, Pale_Rider and 1 other person
MrP said:
(I posted this same message at GTA - not sure which site would have more evanix users who might be interested in this. I would be happy to share the stl files though there is nothing at all complicated to these simple parts).

I’ve been enjoying my .357 evanix Rex, which is powerful and quiet compared to my previous foray into .357 airguns.

It still puts a hurt on my ears and I don’t like wearing protection if I can safely avoid it.

The Rex has a really large shroud with lots of volume but it is purely cosmetic and non-functional, and this pisses me off more than it should. I think it is a missed opportunity. I have a can I can put on the end but there are a few reasons I don’t like that solution either so I am going to try making the shroud into something functional, allowing air to expand back into. 3d printer makes it possible!

Problems to fix:
1) front bushing isn’t vented
2) shroud has a bunch of large holes drilled in it for looks rendering it useless
3) end cap isn’t contoured to shunt air backwards

So I am printing a vented barrel bushing, a long tube-like insert to nest in the bottom part of the shroud and block the holes, and a baffle for the small chamber at the end which I hope will strip and force air backwards.

The baffle I think can be improved - I will likely redesign that part.

Two pics attached, one of the parts in tinker cad and another of the shroud. Right now I’m just printing prototypes to test for a fit. I may try to incorporate some O-ring grooves to get better seals against the shroud in future iterations

My hope is to get more of a muffled report, not aiming for anything other than “shooter friendly”. I am very curious to see how much change there is and to what degree just allowing air to flow back into a shroud will quiet things down.

View attachment 301791

View attachment 301792
Click to expand...
That’s a great idea. I’d be interested to see how it all work.
 
Upvote 0
The prototype fit is pretty good. Added one layer of gaffer’s tape to the sleeve that covers the shroud holes to get a snug fit as it was a little under-sized. The barrel bushing needed to be tapped with a mallet to seat it on the barrel, but that’s actually what I was aiming for as it is quite snug and similar to how the stock bushing was seated. I will have to test with and without the baffle - not sure if it really improves anything or just takes up space.

And I just fired it again and it’s definitely quieter - the hammer and tank ping is now clearly audible - and the impact was as loud as the report. Neither of these were true with the stock bushing and shroud.


I can send you the prototype files now or if you wait a while I can share my next iterations. I have a few small modifications I want to make to streamline some things, improve fit, and make a couple of changes to the baffle.

Edit: M2 is printing now. I tapered the vents on the barrel bushing to improve air flow and adjusted the baffle to have a larger gap between the muzzle and where the “soda straw” part of the baffle starts - trying to allow a little more room for air to expand.

90CF4338-8825-46D4-A16D-DC392A2B70DF.jpeg
 
Last edited:
  • Like
Reactions: Great-Comfortable461
Upvote 0
Tested the second version of this with tapered bushing vents and some other small changes. Fit is a little more snug. I don’t see any improvement over the prototype in terms of sound reduction.

One small change I want to make is to have the “sleeve” thread onto the receiver (one quirk of the Rex line is the receiver has threading for three different diameter shrouds, narrow, medium, and fat) and on my gun the narrow and medium threads are unused, as it has the “fat” shroud.

I should be able to thread the sleeve onto the threads for one of the narrowest shrouds instead of a friction fit like I have now.

Another thing I was thinking is that the barrel bushing and the reflex baffle might function better as a single part, a mini monocore setup combining the barrel bushing and air stripper smoothly contoured to shunt air backwards.
 
Last edited:
Upvote 0
Updated bushing and baffle design to push air back more effectively. Or so I imagine. In this case I went for a “fin” design for the bushing because it doesn’t seem to need to be particularly strong based on my understanding of the gun.

Now I’m wondering if that sleeve had some baffles in it that made it easy for air to flow in but harder for air to flow out, if that might soften the sound a bit more. Or I could stuff fabric or sound absorbing materials in there. Maybe not going to make a huge difference but something I might try at some point.

67AEB165-8037-48A1-9CD0-C449BDEE44E0.jpeg
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu