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Posted: Mon May 28, 2007 7:04 am
by VH_man
yep, those welts are exactly what my gas rifle leaves point blank. those bb's are coming out of the S400's barrel at most likely around 450-500 FPS.... ow.... i have been shot with my gas rifle from aobut 50 feet and that hurt ALOT, i cant imagne the s400 from that close......

also, airsoft shotgun sprays arent that effective. at about 20 feet the bb's start spreading out of control. closer than that, however, and youre SCREWED. i used my spudgun as a peice of artillery once and i found i could NEVER hit anyone from 100 feet. kind of saddening.

Posted: Tue May 29, 2007 12:57 am
by rna_duelers
Ouch,and you guys are dickheads!Well I supose I let my mates shoot me with grapes....But anyways,man that looked not so bad on the video but when you saw the picture at the end......Wow....Painful..And were do you get those BB's?

Posted: Tue May 29, 2007 2:28 am
by jackssmirkingrevenge
Modderxtrordanare wrote:Though you don't live in the USA, (Austrailia?) it should be ok. (?) I dont know the laws there.
I think he'd get into trouble just for owning the launcher, whether it has a silencer or not.

Posted: Tue May 29, 2007 3:01 am
by jackssmirkingrevenge
This is what the internals of the Weihrauch airgun silencer look like, it's considered by many to be the most effective airgun silencer available on the market.

Image

The "foam" around the plastic mesh (yes, they're reffered to as "hair curlers" :roll: ) is very similar to scouring cloth used for washing the dishes.

Posted: Tue May 29, 2007 3:46 am
by chaos
hmm i just tried it at 100psi without any foam at all and with 3 different sized chambers and it seems to be working great like 10 times better than with just foam

that silencer jack is what i need to make for sure all i need to do is get something similar to those lol "hair curlers" and ive got plenty of scouring cloth ill see what i can do.

Posted: Tue May 29, 2007 3:54 am
by rna_duelers
I just finished my knock up silencer using some 3/4 polly pipe with a 40mm outer casing.It works really well for what it is but I am going to attach baffels to supress the sound further till I find a good ratio or best silencing configuration.

Ohh and what design is your silencer now?Does it have baffels?I'm on a need to know basis here,as silencing is very trik.

Modderxtrordanare,get a cock in ya.

Posted: Tue May 29, 2007 4:00 am
by jackssmirkingrevenge
chaos wrote:all i need to do is get something similar to those lol "hair curlers"
An easy solution would be to roll an appropriately sized tube out of wire mesh like insect screen or chicken wire ;)

Posted: Tue May 29, 2007 4:11 am
by jackssmirkingrevenge
rna_duelers wrote:I just finished my knock up silencer using some 3/4 polly pipe with a 40mm outer casing
I suggest you make it longer with slightly larger/more holes and have it separated into at least three separate compartments.

Posted: Tue May 29, 2007 4:15 am
by chaos
im not using any baffles atm and it seems to work better than it did, but i got 3 seperate chambers inside the silencer not just the one anymore.

Posted: Tue May 29, 2007 4:23 am
by jackssmirkingrevenge
chaos wrote:im not using any baffles atm and it seems to work better than it did, but i got 3 seperate chambers inside the silencer not just the one anymore.
Er... technically those washers that you're using to separate the chambers are called baffles ;)

some cool silencer pics for inspiration are collected here

Posted: Tue May 29, 2007 4:29 am
by rna_duelers
I mentioned the idea of using those little chambers :wink: and I am going to add baffels to my silencer and it has 56 holes....Does it need more?lol and I would of made it longer but it's what i had at the time to work with plus it's only a knock up.

Isn't 56 holes in silencer 150mm long enough?and they are 4mmholes.


People,how about we go on the Chat now?Have a little discusion I am on there right now.

Posted: Thu May 31, 2007 12:22 am
by Bubba05
@Modderxtrordanare
Dude where the hell do you get off mate? I'm really interested in "old tech" coz I wouldnt have the first thorght of how to make a pnematic and it's blokes like chaos that are showing me how through posting there guns. I mean i must be a bloody neanderthal coz all ive ever built is combustions. Get off ya bike mate I mean your only been here a short while and your choppin people up over how old school choas is with his?
Get over your self.

@ Chaos mate keep up the good work thanks to you and a few other boys im getting a better understanding about how to make and how pnematics work. Thanks heaps mate and your gun looks sweet and I love you silencer it looks sweet.

Sorry bout that guys but im sick of comming here only to see people rag on other people.

Have a nice day

Bubba

Posted: Thu May 31, 2007 9:49 am
by mark.f
Heehee... back on topic.

A main thing in designing a silenced airgun would definitely be C:B ratio. First, choose an operating pressure that you would use all the time, like 125 or 150 PSI. Or, if you own a small shock-pump like Jack or Chaos, maybe 300 PSI. Then, choose a barrel length. I always choose a barrel length before a chamber length, because it has more of an effect on performance than chamber size.

Now, you need to design the gun so that the air in the chamber expands to the volume of the chamber and barrel when decompressed to atmospheric pressure. Ultimately, you would loose a few fps because the average acceleration of the projectile over the length of the barrel would be lower, but you can compensate for making the chamber volume expand to just a LITTLE over the volume of chamber and barrel, like maybe 1/4-1/2 liter.

This, ultimately, makes it easier for you to silence the meager report created by this type of gun, if you were so inclined. A simple "Wild-West" silencer, which is pretty simple, but very effective. One could make the specially shaped baffles in this design by hammering the center of a washer with a blunt metal object. Further hammering to extrude the center lip could bring the I.D. closer to the diameter of the projectile, but you'll want to leave a little space so you don't destroy the silencer. Then, you can simply solder or weld the washers inside some 1" copper tubing, (or smaller, depending), to make the actual silencer, and thread a compression nut into a bushing on the end of the tube to connect to your barrel. You should make the silencer so that it'll contain the extra air volume after the barrel after expansion, and a little more volume to account for the inertia of the column of air.

<img src="http://www.pyramydair.com/site/articles ... am-web.jpg">

Posted: Sun Jun 03, 2007 1:20 am
by chaos
yer im still having a go at this but im not as interested about it any more,

my questions are now:

1#how much volume should the can have? my guess is the same or 2X the volume of the chamber

2#could i use steel washers as the baffles? ive been using 6mm rubber sheet
cut into disks atm and they seem to come out with the air.

3# do i need to have sound adsorbent material inside the can?

help is greatly appreciated

thanx

~chaos

Posted: Sun Jun 03, 2007 4:44 am
by jackssmirkingrevenge
1) as big as you can afford to make it - there's no maximum volume for silencers

2) steel washers make ideal baffles, I use then in the silencers I make for commercial 0.22 and 0.177 airguns and indeed in most commercial silencers this is what you'll find. You can make them more effective if you separate them with springs instead of spacers, like the "sound biter" silencer attached.

3) You don't *need* it but most agree that the right stuff does have a significant effect.