I thought it might be an idea to include this here for info.
Shrouds/silenced shrouds: a deep dive to answer some questions!
I make a lot of silenced shrouds for people's guns and get a lot of enquiries about them. I have come to realise that people are often confused about just what they do and are capable of, so I thought I would try to clarify.
What is a shroud well a lot of newer guns come with various types made of various materials and some with and some without some form of sound damping some good and some not, generally the STD ones are often metal but more are being made from carbon so to take advantage of the light weight and the rigidity.
I am often asked Will it make my gun quieter .....deep breath. This depends on an awful lot of factors, the first being and probably the biggest influence, length and diameter and secondly, material.
Now 60% of the time a shroud is used for looks with silencing coming a close second and a lot of people want it all, fair enough and in most cases its possible but only if the form and function can be accommodated in the design, I get asked can I have a really quiet shroud, but I only want it to be this length/diameter, and a lot of the time the answer is no!
In order to have a nice quiet shroud, it needs to project enough beyond the end of the barrel to accommodate enough damping material, regardless of what this is, and secondly it needs to be of a sufficient diameter to be able to dissipate the air blast that actually makes the noise you're trying to quieten.
Some guns such as AA HFT500 have such a small clearance between the barrel and cylinder that it almost impossible, I say almost because I make these, and they actually take a fair bit of the crack out of the guns firing cycle the same goes for the FTP900, and there is usually a stipulation not to go too long as they have to fit into bags or cases which limits the available space to cram in the sound deadening.
This is a factor in a lot of shrouds, and a lot of the time it's because people want a good-looking shroud of a certain length/diameter, but as quiet as possible, so you can see the problem.
This can also apply to larger diameter shrouds like to 50mm fitted to the Vixen which is in its STD form is guilty of not being very quiet, and I have made shrouds for these but because of the inherent resonance of the large diameter no matter what you stuff it with it is still not as quiet as fitting a dedicated silencer.
This leads me to the materials, I normally use carbon tube as its light and very structurally stiff, but this has its own properties and if not damped on its mountings I use O rings as this isolates it well, and I don’t like visible grub screws, but it still has a kind of ring depending on its length/diameter, but it's still quieter than its metal equivalent.
Finally, we come to construction. People often ask about back venting, and despite a fair bit of testing, I have come to the conclusion that it's no better or worse than the STD configuration, and just overcomplicates the design.
so I don’t bother, so I think that just about covers it, I like to make shrouds with nice clean lines and don’t make double diameter type as IMO you may as well just add a moderator to the end of the shroud/barrel and for me the whole idea is looks and convenient in that you don’t have to remove a moderator to get the gun in the bag/case and it looks good doing it.#
Addition: I have had occasional reports that a shroud has come off the friction O ring mounts and found two things 1: that some guns seem to shift a lot of air on firing and can overcome the friction of the retaining O rings and I have started to fit larger section O rings to provide extra grip ( note this is only certain guns that can do this)
2: The main cause seems to be that people seem to be addicted to coating O rings with silicone grease/oil this is a complete no no when it comes to friction fit O rings if you find the shroud difficult to get on and past the O rings use a little wash-up liquid/water or even a bit of spit if you finding it difficult.
I almost never use external grub screws in my shrouds as I find it spoils the look IMO, normally the only gun I will use one in the base fitting is the AA HFT 500.
Hopefully, this goes to answer some of the questions and preconceptions some may have.
