co2 dump, how fast can a co2 be emptied?

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twitchmastr
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Fri Dec 12, 2014 10:54 am

I've had an idea recently that involves using an entire co2 cartridge to fire one high powered shot. The basic idea is a custom tip that houses a pellet in the front, and a co2 punch in the rear. The fitting will slid freely over the neck, and spring piston would be used to apply force on the rear of the cartridge.
My concerns are how fast the gas could fully be released with variables including barrel length to ensure max pressure is achieved and also creating big enough hole in cartridge. Thoughts? And yes I am aware this is a very expensive method. I don't care about that.
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bravootome
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Sun Dec 14, 2014 10:11 am

I understand you want to hit directly from the cartige without a chamber ?
...it will maybe work but you will waste lot of co2 in vain.

First the hole of the co2 cartige is very small and second the projectile will be hitting the target and the co2 from cartige still trying to get out of it.....
come undone
twitchmastr
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Sun Dec 14, 2014 11:00 am

This is a crude diagram, there will be a chamber with a locking mechanism.
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matti
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Mon Dec 15, 2014 11:43 am

I have made a pistol that launches a 12g co2 cartridges by piercing then with sharp firing pin, but they did fly only about 10 meters and they still would not be empty before they hit the ground.. I don't think they will work with your setup, unless you made a small expansion chamber and a detent to hold the ammo for pressure build up in the expansion chamber.

Other way to make this work would be possibly to build a hammer valve with a low volume chamber and use a 12g co2 quick change adapter, design help you could find here.

Also problem is that when you emty a co2 cartridge or bottle fast it gets very cold and that drops co2 pressure very much :wink:
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Brian the brain
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Mon Dec 15, 2014 2:29 pm

You could use a coaxial design,
Load the cartridge from the rear, snug-fit inside of a hollow bolt.
The barrel diameter should be smaller than the cartridge/ I.D. of the bolt.
The barrel should be fitted with a seal on the breech.

Close and lock the bolt.
Have the cartridge be pierced apon locking by a long needle.
It will drive itself towards the barrel by the expanding gas.

gas leaks past the cartridge filling the coax-reservoir.

Then, after pressurisation, dump the volume behind the cartridge and have it act as the piston by driving itself further into the needle and opening the passage to the barrel for the pressure stored in the coax-reservoir.

After the shot, retract the bolt, perhaps even ejecting the cartridge.

With a projectile stuck to the front of the cartridge you have selfcontained ammo.

Bit costly though.

I'll see if I can work out a diagram.

Here's one where the needle is pushed back away from the cartridge after peircing, and the needle also acts like a hammervalve to pilot the cartridge/piston.

The idea is once you cycke the bolt, a stopper in the rear stops the center part of the bolt while the outside keeps sliding back, ejecting the cartridge.
You'll need very good O-rings and a strong bolt-lock!!
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Gun Freak wrote:
Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!

Can't ask for a better compliment!!
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jimmy101
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Wed Dec 17, 2014 5:27 pm

Isn't a 12g CO2 cartridge filled with liquid CO2? The flashing from liquid to gas is pretty fast but perhaps not fast enough to make the system worthwhile. You might want to use an expansion chamber.
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