Although this is very simple it is very powerful and very effective.
Most credit goes to a guy over at spudfiles.com for this idea. I just remade it and put a barrel on it.
It is a cheap 7.00$ fire extinguisher I bought a walmart. This extinguisher has a screw on top so a schrader valve can be put in it. I put the schrader valve in it, screwed on the top and tested it to 90 PSI. It had a monster kick to it, but the guage didn't even budge. The guy on spudfiles said it could go to 200 psi. I got a bike pump and practically had to jump on the pump to move the pressure guage. But eventually it said "full." I'm guessing I got it up to around 150 psi. I'm guessing, I heard it was almost physically impossible to pump after 120 psi. Well, now I have a powerful air source, but what to do with it? I filled it up with water and it made a killer super soaker but it got boring after a while. So, I put a barrel on it an voila! A medium sized gun capable of 7 shots at around 90-100 ft. flat for each dart. Sometimes though I press down the button to long and waste air. ut This is all I would ever need in a war. But I don't go to wars.
Schrader Valve.
