Shrouded vs. moderator?

[Triggernosis]

What are the benefits of a shrouded barrel (Mrod, FX Dreamline, etc.) vs. a barrel with a moderator on it (Weihrauch HW100/110, Diana Stormrider, etc.)?
I'm sure there are advantages and disadvantages of each - but I don't know what they are.

 

[austin870]

Shrouded is typically louder but you get a nice short barrel that is easy to handle. Moderator you get long fishing pole length barrel but better sound supression. A small amount of guns like a Daystate Regal has managed to have a shroud with a short moderator keeping a compact gun. Most guns especially like the HW100 are reduculously long. You won't even find the spec on length for an HW100 moderator version. I believe the carbine comes out to 48" which is no carbine to me. The Sporter HW100 is a freaking surf pole over 50".

I think most of the conventional rifles have to go to a shroud/moderator. IMO the term carbine has all but lost its meaning with most manufacturers using just a long moderator. The bullpups bypass this problem because with those you can can have a long barrel and long moderators but keep the overall length down. They have a linkage type system.

 

[austin870]

Prefer shroud.

Me too unfortunately most manufacturers are going to the fishing pole with a long moderator. People seem to be more concerned about noise than a managable length. Mainly the track home shooters surrounded by houses. Just make sure you get a shrouded barrel that is threaded for a moderator to be added if you have serious sound concerns. 

 

[Long_Gun_Dallas]

A shroud will usually capture a lot of the exiting pressure from the barrel, reducing report. It can make a huge difference in noise level with a moderator versus a mod with no shroud. Some custom moderator designs even incorperate a partial shroud to increase expansion volume for muzzle preasure. 

One of my guns incorperates an air stripper and baffle stack into the shroud (as do some factory guns, too).

But my hatsan had a shroud that was used exclusively for barrel tensioning and had zero function for reducing report.

Ideally you would want a shroud to be both tensioning (improves accuracy) as well as spund dampening. (air stripper deflects preasure backwards into shroud and strips turbulence away from projectile) some older fx barrels used this type of internal air stripper effectively making them pretty darn quiet for having no mod.

 

[dizzums]

its mostly length as stated .. bench warmers probably dont care very much and a shroud + a moderator is super quiet ... but trying to tuck a gun thats longer than you are through the brush hunting is a big minus and in most circumstances where you got to reposition for a shot a very long gun is going to slow you down and make it harder to set up ... some guns pull it off well though, like the prod for instance, its alittle too noisy to be shooting right up on the neighbors fence with just the shroud, add the sumo to it and your good to go .. just dont shoot out their window or something lol ...

 

[qball]

No all shrouds are designed equal. Most shrouds have just an air stripper, it helps a little with noise but primary function is to trip turbulence to increase accuracy. These shrouds only extend an inch pass the end of muzzle/barrel.



then there are shrouds with build in sound suppression but they always extend a few inches pass the end of the muzzle/barrel. They will have air stripper and baffle, with out baffle there won’t be much sound suppression at all. It also need length and volume to provide any noticeable sound suppression so generally speaking most factory shrouds are there to improve accuracy with slight sound moderation. Edgun L & L2, AGT’s vixen and uragan king have massive shrouds so they do provide more than basic sound suppression. But at the end of the day is about same effectiveness and almost length as a screwed on small moderator plus shroud. If you want really back yard quiet sound suppression you will end up adding a big moderator regardless. 

 

[john8]

Why not both, my K1s have an effective moderator built in to the shroud, series of cones and washers that appear to be bonded metal beads (I know that is probably not right but that's looks like to me). They are very backyard friendly, throw on a moderator and they approach mouse fart quite.

 

[Colorado_CJ]

My Taipan Standard .22 shroud is very effective at sound control, so some do it right!

I will say, coming from a powder burner background, these airgun suppressor internals are built VERY differently than what I am used to when looking at baffle stacks.

Don't know how they work so well with just a few washers and spacers.

 

[heavy-impact]

Noise comes from high pressure air/gas escaping. To make a gun quiet you need to let the air/gas expand until it's pressure is low enough to be under your desired sound level when it escapes to atmosphere. The lower the volume/quantity of high pressure air/gas you start with the smaller the area it needs to expand to reduce pressure to the desired level. So low powered guns can get by with just a shroud for the gas to expand into while high powered guns will need increasingly larger volume as the power level goes up. Delaying the exit by increasing length helps and redirecting the sound waves inside the shroud or suppressor helps as well. Anything above the speed of sound (1124fps at sea level) will make a loud sonic crack that you can not control. All this applies to powder burners same as airguns.

 

[CyberDyneSystems]

Both is more betterer!

 

[heavy-impact]

Both is more betterer!

There is a point of diminishing return so you don't want your gun to any longer than necessary. I prefer steep cone baffles as close to bore diameter as possible without clipping. That outperforms felt in a jug by a mile.

 

[MrP]

This is a complex question actually. I think the best thing would be to have a shrouded barrel and an LDC that that strips air and vents it back into the shroud. This only works if the shroud and moderator are integrated in design together in some way. Some folks make these and call them "reflex" LDC's.

If you can't design them yourself and are stuck picking one or the other, well the shroud is limited by the design of the gun but the moderator can be any length and diameter you want.

For me the best by far is a moderator that vents back into a shrouded barrel which is what I have on all of my air guns. I had to build this myself though. This allows you to have a shorter overall length and excellent sound suppression because a lot of the volume to capture the explosive air release is actually behind the baffles in the moderator.



I can post images and details of some of these designs, stl files, if anyone is interested.



[looks like some already said what i just said before i got here... should have read the whole thread before posting] 

 

[Nutcracker]

Both is more betterer!

I like that, that is funny. 

 

[austin870]

I believe he is talking about factory rifles currently available. Of course there are lots of custom options. My custom AZ built Rapid 25cal is pushing 60ftlbs and all you can hear is the hammer which is real quiet too. Touted to be "mouse fart" quiet. On the other hand my HW100 FSB in 177 with shroud at 20ftlbs has a little bark that is quite noticable but still at the outer area of backyard friendly. The Rapid is also quieter than my Daystate Regal with shroud and moderator at 18ftlbs which is very backyard friendly. 

You don't need a big goofy moderator if the shroud is built correctly but obviously that is not cost effective for the manufacturers. Thus you get big goofy moderators and lots of inches added to gun length. They are cheap bought in volume by manufaucturers and just screw right on so no labor involved either.

 

[JungleShooter]

Both silencers and shrouds add to the length of the gun.

So, a gun that has a bare barrel and uses a silencer to quiet it down gives you the option to make the gun shorter quickly and without tools, e.g., shorter for transport, or for shooting where noise is not a concern (though you might consider ear protection...).


However, if you want the option of quieting your gun down as much as possible, the shroud will do a marvellous job when combined with a silencer. It is large and can take up a lot of air that otherwise the silencer would have to deal with alone.


For that reason: If you want both quiet and short in a gun, shrouded guns will be better (all other things equal).


I personally find guns with a "thick barrel" (that is, with a shroud) better looking than guns with a drinking straw barrel and a dumbell of a silencer hanging off its end....



Matthias

 

[L.Leon]

On my shrouded .22 Bantam Sniper HR I have used it with and without a DonnyFl Tanto. I've gone back to just the shroud as I save 5" in length, the gun is more maneuverable and just as quiet. My Compatto on the other hand absolutely needs the Tanto to be backyard noise friendly. It's going to depend on the gun. To my mind what's the point of a shrouded PCP if you're still going to need a moderator? Why not just extend the shroud or shorten the barrel or both?

 

[sasquatch]

I want both options. I want the shrouded barrel that can also take a moderator. To me it's not a versus question because most modern rifles can do both. If not one or the other will do. But if I need a Donnyfl Emperor then it might not matter if barrel is shrouded. Does that help? 



For the maximum amount of noise reduction get both.



This becomes more apparent the faster the projectile is and the higher the caliber.. But sometimes short vs long barrels will make a difference too.



Some guns also just have noisier action. So don't think the moderator or shroud will fix that... 

 

[CyberDyneSystems]

My quip was not just being flippant. I picked up a DonnyFL tanto for my already shrouded Kratos .22, and the difference is pretty impressive. All I hear now is the firing pin/hammer and impact on target. Stock with the shroud it was not bad, but the LCS has really made it fully backyard shootable.

 

[MrP]

I've noticed the same thing with a talon ss i have. Very quiet with the baffled shroud, but with a small LDC on the end it is so quiet it is surprising. The first time I tried it I actually thought the gun had misfired.

 

[Bobbylee]

I use both on my Flashpup for backyard and shroud only for hunting, no problem!