Tranquilizer Dart Gun

I DO NOT USE THIS WITH ANY ACTUAL TRANQUILIZER. I DO NOT SHOOT AT PEOPLE OR ANIMAS. A PVC dart gun that shoots a specially designed syringe cartridge that fits snugely in the barrel. The tank is pressurized to 120-130 psi and the sprinkler valve releases the pressure all at once, propelling the dart up to 100 yards at a very high velocity. The gun can shoot short distances at 20-30 psi. The valve is actuated with either a sprinkler timer or a 9 volt battery. The recoil from this gun is insane. It almost knocked me over a couple times. Aside from a tranquilizer dart, this gun can shoot water bottles, AA batteries, screwdrivers, blow darts, fireworks, anything that fits down the barrrel.
Sorry i didn't put up an instructable to make this, but by the time i thought of that, the PVC cement had already dried.

To make this you need
* 1/2"X2' PVC pipe
* 1"X2' PVC pipe
* 1/2"-3/4" threaded coupling
* 1"-3/4" threaded coupling
* 3/4" sprinkler valve
* 1"-1/2" T coupling
* 1" end cap
* 1/2" end cap
* 1/2" male compressor coupling
* 1/2" female compressor coupling
* 1/2" nut (inside 1/2" end cap to hold female compressor attachment in place)
* old airsoft gun hand grip (optional)
* momentary push button switch
* some speaker wire
* sprinkler timer or 9 volt battery
* PVC cement
* thread tape
* bike pump/ air compressor
* a couple hours of time

Approximate cost: $30 (with 9 volt)     $70 (with sprinkler timer)