DIY FX Impact .22 shroud for use with standard 1/2" 20 UNF moderator (in theory)

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fe7565

fe7565

Member
Oct 13, 2015
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VA, United States
DIY poor man's temporary shroud to be used with a standard 1/2 " 20 UNF moderator. This is only theory for now, but looks like all the things line up, at least for a Daystate Airstream moderator that was designed to go over a 22mm shroud and screw into the 1/2" 20 UNF male at the end of the shroud.

The .22 FX Impact has a 14mm OD barrel and the fixed shroud that is near the action has a 25mm outside diameter and a 14.22mm (or close) inside diameter. The naked barrel has a 1/2" 20 UNF male end. When I take off the factory extendable shroud and screw on the standard aftermarket moderator (mine slides over the barrel a few inches) there is about a 11-14cm gap between the action and the moderator. So I had a piece of 1/2 PVC pipe around that can be slipped right on to the barrel and also inside the moderator. There is just enough gap that you can place an o-ring on both ends of the PVC. One o-ring inside the PVC at the action end and another o-ring on the outside at the moderator end. May want to add another o-ring in the inside of the PVC at the moderator end. To finish, slide a black heat shrink over the PVC as well. For extras, can add couple of tiny nylon screws (allen screws) to secure the "shroud" to the barrel but the screwed on moderator has it wedged anyway.

I do not think enough pressure blows back to harm the PVC...what you think?








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This is for those who already have an existing moderators which simply screws on the naked barrel. The shroud in this case only covers up the gap between the action the moderator, not sure how much silencing it would do since the rest of the barrel towards the rear is naked as well.

In my particular case the Daystate Airstream moderator does exhaust towards the rear as well. However, with the Airstream on it the entire FX Impact is only 26.5 inches in length which is the same length as the Vulcan .25. The naked barrel is 19 inches long.


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FE the idea of venting into a shroud is to aid in reducing the report of the gun, it is not just for looks. By using such a thick PVC pipe you will most likely get a negligible difference in the report if it is vented, If you are using o-rings to sit the shroud on then there will be no venting into the shroud and it is just for looks. If you use a correctly made shroud the difference in the report in conjunction with the Airstream will be noticeable. I do not give advise to members just to get business, there is a reason that shrouds are made the way they are, as it is some are not very well vented, so some shrouds available are better than others. I, Neil.
 
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Neil, no doubt it's mostly cosmetic to use the thick PVC as a shroud, especially with the o-rings. The Airstream moderator seems to have been designed to vent backwards inside its own housing when used with my Daystate MVT (similar to the MCT). It was designed to slip over the 22mm shroud that has already some baffles inside. The shroud-end of the Airstream is around 22.33mm ID and has an o-ring that seals the mod to the 22mm shroud. The Daystate factory shroud ends with a 1/2" 20 UNF male opening, so any air going backwards from the moderator has to go back via the 1/2" 20 UNF opening through the baffles inside it.

As you pointed it out, with the Impact if the shroud is not designed properly the air will be trapped inside the Airstream itself and will make the report much louder. So there needs to be shroud that fits inside the 22mm rear opening of the Airstream but also makes use of the air space between the 22mm OD of the shroud and the 14mm Impact barrel.

Of course, the best thing would be to make a moderator/shroud combo designed for the Impact from the ground up...
 
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FXShooter makers only make what there is a demand for, if someone contacts me to make something for a specific gun I will always try and oblige, as for being a guinea pig, that makes no real sense. If I make something for a particular gun I can assure you it will work, otherwise I would not still be backed up with orders. If someone wants something for this particular gun and I think a shroud would work better I would suggest a shroud, if I think a 2 piece shroud is called for and the customer wants the quietest option he can get I would suggest it. But as a maker I always have to weigh up the options and what the customer is asking for, does he want as quiet as possible and does not care about the cost, or, does he want something quiet and is budget conscious? I often see things posted that I have made, but there is not much call for, so what you are seeing could well have been made before, I do not post online every option I have ever made, if someone has a specific request they just need to ask, Neil.
 
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Furthering Neil's intial point, I managed to make a shroud with reflex function with an airstream silencer on my crossman 2240XL. The quintessential $100 gun.

You need good volume for the exhausting (backwards) Airstream, so I sleeved the 30mm outside of the silencer with some bicycle inner tube, so that a 31mm inside diameter solvent weld plumbing waste pipe would fit snugly over it and back towards the action.

The pipe is also 36mm OD. I don't know how much room you have for a thicker pipe at the front of the Impact's action. Even if you had to sleeve back down to a stub of a pipe similar to your first one, you would be getting proper exhaust into it.

N.B. I'm happy using the plumbers waste pipe on my Ratcatcher (UK name), but think the Impact might rupture it at full power (so what?).
 
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FX shooter it is quite possible someone has had one built, unfortunately I make so many shrouds and LDC's now I can not keep track of what guns I have made them for and what guns I have not. I use excel spreadsheets to enter and keep track of my orders but I am not sure what software would be needed to keep track of everything I make and be able to access individual custom builds to get details of the builds. It is not a big deal for me to make a custom shroud for an air rifle, all I need is a few dimensions from the customer and possible a picture or two to make sure that there are not going to be any obstructions that need to be got around. The build concerned for this members gun looks very simple and should not be difficult at all to make, Neil.
 
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Hi 
I'm also using fx impact. I would like to attach the barrel directly to the suppressor. I want to know how to attach it. What type of connection need to be used. What is the size of the suppressor .have anyone used. Please share some details about this with me

What connections can be used for. 22 barrel. I am already having suppressor for that but I can connect it using shroud only. I can't connect it directly to the threaded barrel.
 
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