suppressing a BBMG?

[JDP12]

Hey all- I'm getting started on my vortex cap BBMG, and I really want to make a suppressor for it... I'm not sure how loud it will be, probably not very but it will be running off 12 grams.

So I was just wondering what you would do for making a suppressor- more specifically, making sure the BB's don't hit the baffles. Would you just insert a barrel piece? Then drill it out somehow? Only problem is I can't really see that as an option with a .177 barrel

[ALIHISGREAT]

You could just make the opening int he suppressor larger than the bore.

Or alternatively drill holes in the barrel, this could be problematic on a small bore though.

[covey12]

most of the noise from mine is the bbs hitting inside the cap, not actually leaving the barrel

[POLAND_SPUD]

so you're using a .177 barrel from an old airgun, right ?

acctually I built a ghetto silencer a few hours ago but for a marble caliber(16mm ID 18mmOD)... and it works pretty good at dampening the sound to an acceptable level)

first I found a plastic tube that fits over the barrel tightly so it is like a kind of adapter on the muzzle

then I attached a steel tube ( 20mm ID) from and old bike pump over it.... earlier I made lots of perpendicular cuts on it... naturally, it needed some outer casing to trap gasses so I used two 1.5 L bottles cut to fit the length... and finally I stuffed lots of packed cloth inside (it didn't worked without them, possibly because there are no baffles on it)



I think I could build it much easier, cleaner and better with a copper pipe with an ID of 18mm...

could you give the OD of the tube you use?

[JDP12]

No actually it's a brass tube I got that fits NBA perfectly. The OD I'm not sure of just barely bigger. It fits almost perfectly in brakeline so I was gonna sleeve it in that
J

[POLAND_SPUD]

now that makes things relatively easy... just use a longer brakeline than the barrel and cut holes in the length that extents past the muzzle... I don't know how long should it be really or how many holes you have to drill

I made cuts with a dremel as I don't have a drill press... I suspect that adding baffles would improve performance... packed cloth worked all right for my purpose but it just dampens the bang (but still it does it very well... a 150 psi shot sounds more like 100 psi one... actually It seems that I most noise is coming from the pilot port... I PM you a link when I film it tomorrow)

JSR mentioned that silencers should work better without any material packed... since I experienced something different I suppose that's simply because mine has no baffles at all

[jonnyboy]

I think your silencing ability is going to highly depend on what kind of flow your compressor outputs in a short amount of time. Suppressing a 1/4 gallon of air is going to be a challenge on a bbmg without the silencer being massive.

[JDP12]

Try 12gram LOL

[jonnyboy]

Try 12gram LOL

There gas is anywhere from 700+ psi depending on temperature. How many ci is your chamber? From there you can tell how many psi a 12 gram will give you.

[JDP12]

It's 2.65 so 800 psi or so. But it's a bbmg so actual pressure won't be that high

[jonnyboy]

It's 2.65 so 800 psi or so. But it's a bbmg so actual pressure won't be that high

If I remember latke (I think) did a test with a gauge on the chamber. I want to say he was using 110 psi and the gauge read 60 psi. A little over half the pressure, how this scales I don't know but that's still alot of gas to contain in a silencer that's not ridiculously big.

[POLAND_SPUD]

yeah jonnyboy is right I remember that too - I suppose it was even lower than 60 psi...
but on a BBMG with a detent there would be more pressure to deal with... it might be a good idea to build one and if you do you really might need a silencer on it

but that's still alot of gas to contain in a silencer that's not ridiculously big

yeah that's a lot of air... sure there are restrictions that limit the flow of gas... also, when a BB passes through the barrel there forms a pressure rise that generates noise

on the other hand, ROf is usually quite high and there is a lot of air being pumped through the gun... you know even a blowgun will generate some noise
so there are lots of those small bangs per second... air enters the silencer via teh barrel (which has an ID or .117) and it leaves it via only a slightly larger hole... so my question here is -> wouldn't it be a good idea to add small vent holes packed with cloth or cotton that could vent more air than just the muzzle of the silencer?
I know that JSR said that there shouldn't be any holes in the silencer tube but does the same rule apply here ??

[jonnyboy]

I know that JSR said that there shouldn't be any holes in the silencer tube but does the same rule apply here ??

I think he says that because each hole robs the projectile of air and ergo the shot has less power. BBMGs's aren't in most cases created for shear power so a little velocity loss shouldn't matter much.

[jackssmirkingrevenge]

JSR mentioned that silencers should work better without any material packed...

Did he? It's subjective really. Many judge the effectiveness of suppressors in the same way the judge recoil, very rarely using decibel meters. In any case sometimes it's not just the loudness that counts but the way the sound is changed. In this manner, some people report better results without packing, others don't.

I know that JSR said that there shouldn't be any holes in the silencer tube but does the same rule apply here ??

Always

In general BBMGs are easier to suppress because it's not one big muzzle blast but really the volume of air between one BB and the next. Adding holes to the outside of the can means that the air has less time to expand before it exits to the atmosphere, therefore it will exit at higher pressure and make more noise.

[JDP12]

I was wonderin when jsr would pop in here.... But I see what you're saying. Construction should commence by friday

Also what would you recommend for diameter and length? I was thinkin maybe 1 inch pvc and maybe 5. Inches long. Or I was gonna do a shorter one of 1.5 or 2 inch PVC but only 3 or 4 inches long