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Auto Cartridge Gun

Posted: Fri Apr 14, 2006 11:44 pm
by Atlantis
If you took this design...
http://people.howstuffworks.com/machine-gun7.htm
...and used cartridges with one end sealed and one end a burst disk, and put a penetrator on the bolt, wouldn't it become an automatic pneumatic rifle? I know there are legality issues here but I was just wondering if it was possible.

Side Note: For any burst disk cannon, could'nt you just use a spring driven penetrator in the chamber to fire it?

Posted: Sat Apr 15, 2006 12:03 am
by Shrimphead
Ya I think you might be on to something, but the biggest problem I see is filling the cartridges. You can't just go putting a shrader valve on every bullet that an automatic cannon shoots.

Edit
I got it!! 12 gram co2 catridges. Have the bolt pierce the back of them, the pressure of the released co2 fires the emptying cartridge amazing distances, and also creates a blowback system for the bolt. There are a few problems with this idea, though. It would be deadly for anybody or thing in its line of fire, could cause explosions if the cartridge got jammed :shock:, and would end up being expensive. Also, the cartridges going that speed could send shrapnel everywhere upon impact.

Posted: Sat Apr 15, 2006 12:31 pm
by Shrimphead
I came up with a cool air cartridge for this today. You have just a normal length of pipe say 1" with an endcap on the front end. On the other end you have a coupler with a 1"-1/2" reducer bushing. The 1/2" end of the bushing is threaded. Then pinned between the bushing and the coupler you have a diaphragm/burst disk.
To fill it up, you put a ball valve then a 1/2" male adapter on your compressor hose. The you screw the male adapter into the bushing, and open the ball valve. The air causes the diaphragm/burst to flex, which allows the air to pass by. But the d/b can't flex the other way so it make a one-way valve. Then you put it in the gun which has some firing pin/needle that pokes a hole in the diaphragm and causes the air to release and send the cartridge flying. Look at the picture to help explain my idea. Any thoughts on it?

Posted: Sat Apr 15, 2006 1:13 pm
by Atlantis
I think it's pretty self-explanatory. Someone on SpudTech make a combustion version of this. Pneumatic would be a lot quieter and cooler. You could also use the cartridge and ammo seperately, and eject the cartridge and reuse it.

Posted: Sat Apr 15, 2006 1:39 pm
by Shrimphead
Are you going to try building it Atlantis?

Edit
I might try building it if I can design it without any major flaws. I drew up a quick diagram of how it would work. I left out some fittings that just help with the structure of the gun and not the performance.

Posted: Sun Apr 16, 2006 12:03 am
by Brian the brain
About the CO2 cartrigde idea schrimphead...I think it's possible!!

I came up with the exact same idea back in....oh...1997 or something.
The problem I had back then was finding( or should I say funding) all the parts.Never got around to making it.I was a bit scared of the pressure too.

PVC is out of the question if you ask me.You als need something to keep the cartridge from moving while it's being pierced.The hole made by the "striker"should be as big as possible.Don't know what will happen to the direction of the cartridge after it leaves the barrel though.Might still hold some gas and if the exit hole you've created is a little off center....well you know..( bit dangerous!!)using 12 grams of 800-900 psi CO2 will give an enormous amount of power.
Like a water rocket on steroids!!!!

Posted: Sun Apr 16, 2006 1:20 am
by taz22
i'v came up with olso the same id:D buth than instead of a shrader valve i would putt a car tire valve/bicycle valve on it. it would posible work, if the spring isn't to hard. even with this way you could make a full auto combustion.
just spray some deo, butane in a ammo round. use 2 nails en make shure they will have a spark between. i will add pictures later.

Posted: Sun Apr 16, 2006 1:50 am
by CS
buth than instead of a shrader valve i would putt a car tire valve/bicycle valve on it.
Same thing.

You guys just need to hold your horses! My Jedi senses tell me a automatic potato gun is near! (Like a month or so) Also there is already a auto pneumatic on SpudTech...

Posted: Sun Apr 16, 2006 11:03 am
by Shrimphead
Why would we wait for people to do their's first when we can?

@taz22-Nice cannon design, but with your pneumatic cartridges, when shot, the shrader valve will break, and then you would either have to replace that every shot or replace the whole cartridge. My pneumatic cartridge design doesn't have any valves on it, so all that needs replacing is a burst disk. And also, what would you make your magazine out of? You would need to make it out of wood or metal or something. That's why I drew mine with a vertical mag made out of pipe. It's more complicated, but would probably be easier for me. If you can make that spring mag, though, it would be awesome.

Ya pimp, I saw bcpneumatics' auto golf ball cannon, but I don't know how it works. Do you?

Posted: Sun Apr 16, 2006 12:43 pm
by CS
Shrimphead-
Yes, I due know how it works. The thing I didnt realise it had a switch that detects air pressure, and once the pressure reaches 100psi it shoots. So he hooked that doorbell thing in series with the switch. He also left the sprinkler unmodded so that it could be electronically activated. That means when the button is activated AND the pressure is above 100psi it closes and allows current to the soleniod. For obvious reasons after the shot the pressure drops and then the switch remains open till 100psi is reached.

Posted: Sun Apr 16, 2006 12:46 pm
by Shrimphead
That's really interesting. I didn't know that you could get a switch like that. Do you think that this design will work, pimp?

Posted: Sun Apr 16, 2006 1:07 pm
by )DEMON(
taz22 wrote: just spray some deo, butane in a ammo round. use 2 nails en make shure they will have a spark between. i will add pictures later.
what if you just use paper or plastic caps to trigger the combustion,they will be located on the back of the cartidge and struck with the firing pin, the plug is fixed in place and the back bursts off when the cap combusts,or something like this

Posted: Sun Apr 16, 2006 9:13 pm
by Mini Khan
good call, good call

Posted: Mon Apr 17, 2006 12:17 am
by Brian the brain
My design for the CO2 cartridge gun is on this site.http://www.psguns.tk/
Click "Brian's designs"

those designs are quite old ...I've come a long way since then

Posted: Mon Apr 17, 2006 1:58 am
by boilingleadbath
Incidentaly, there is similar combustion-cartrige 'research' being done by a member of the spudtech forums. You may want to check it out. (it's in the combustion section, as you may expect)