sound suppresor idea

[jon_89]

ok so i am going to build a silencer for my half inch air cannon. my idea is instead of drilling holes in the barrel i will have a half inch coupler to a one inch pipe. then some sort of material and then a two inch pipe on the outside. my questions are:
1) do you think this will work?
2) if it does work will it be efficient?
3) will it effect performance any?
4) what is a good silencing material?

thanks

[spud-tom]

um i don't quite understand the entire thing, besides drilling holes makes almost no difference.

[darkmilk]

It is amazing that anything is able to silence a gun, but gun silencers actually work on a very simple principle.

Imagine a balloon. If you pop a balloon with a pin, it will make a loud noise. But if you were to untie the end of the balloon and let the air out slowly, you could pop it making very little noise. That is the basic idea behind a gun silencer.

To fire a bullet from a gun, gunpowder is ignited behind the bullet. The gunpowder creates a high-pressure pulse of hot gas. The pressure of the gas forces the bullet down the barrel of the gun. When the bullet exits the end of the barrel, it is like uncorking a bottle. The pressure behind the bullet is immense, however -- on the order of 3,000 pounds per square inch (psi) -- so the POP that the gun makes as it is uncorked is extremely loud.

A silencer screws on to the end of the barrel and has a huge volume compared to the barrel (20 or 30 times greater). With the silencer in place, the pressurized gas behind the bullet has a big space to expand into. So the pressure of the hot gas falls significantly. When the bullet finally exits through the hole in the silencer, the pressure being uncorked is much, much lower -- perhaps 60 psi. Therefore, the sound of the gun firing is much softer.

compliments of howstuffworks.com
http://science.howstuffworks.com/question112.htm

Merged:

gases exit those holes into this chamber]
[_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ]_____________
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ______________
[ lowering the pressure exiting the gun ]
[_________________________________]


the less pressure exiting the barrel, the less air vibrations or sound waves travle silencing the shot so he does need holes

[jackssmirkingrevenge]

If I understood it correctly, your idea isn't going to work. A suppressor needs to lower air pressure before it exits the muzzle, if you're passing the 1/2" projectile through a 1" the air simply going to rush past it and make as much noise as it made before.

[Pilgrimman]

It will likely decrease performance, just like any silencer. How significant the decrease? I don't know.

[jackssmirkingrevenge]

It will likely decrease performance, just like any silencer.

some silencers will actually increase performance, you can't generalise.

[Novacastrian]

Like Jack said, the air will just go straight past the round.

Edit: What effect will removing the steel wool have on my silencer, it would increase the capacity quite a bit.

[jon_89]

well it would be like a screw on. so when the air gets to the end of the chamber it spreads outwards so how will it decrease performance if the projectile has already left the barrel?

[jackssmirkingrevenge]

What effect will removing the steel wool have on my silencer, it would increase the capacity quite a bit.

On a combustion, I say keep the steel wool. The gasses generated in a combustion are under pressure because of their temperature, steel wool helps to dissipate the heat and cool the gasses down thereby reducing pressure and therefore noise.

how will it decrease performance if the projectile has already left the barrel?

It won't decrease performance, but it won't make your launcher any quieter either.

[Novacastrian]

Thanx jack i'll keep it

[Kenny_McCormic]

If you live in the USA making a silencer is a FELONY unless you pay a $200 making tax and fill out an assload of paperwork.

[jackssmirkingrevenge]

If you live in the USA making a silencer is a FELONY unless you pay a $200 making tax and fill out an assload of paperwork.

again, it's a grey area.

[Novacastrian]

If you live in Australia you can get arrested for picking your nose in public (probly). I say *$@! the beurocrats and their stupid laws.

Rant over.

[jackssmirkingrevenge]

Apparently in the UK these days you can get fined for ashing your cigarette out of a car window. Not throwing the butt out mind you, just ashing. Where will it stop, I wonder

[Rudesill Ballistics]

The patent for Hiram Maxim's suppressor.