If you want to be able to fill your gun with co2 and don't wanna spend $80 on a regulator, just go to
http://palmer-pursuit.com/ and buy a universal fill adapter. You'll also need a safety pop-off valve, a pressure gauge, and a tire air chuck. Install the guage and popoff valve in your chamber, screw your CO2 bottle into the fill adapter (but not enough to let the gas out!), and screw the tire air chuck into the small hole in the side of the fill adapter. Now you are ready to fill your gun. To fill it:
1. press the air chuck onto the tire valve.
2. slowly turn the screw on the top of the fill adapter while looking at the pressure gauge. If the pressure rises, that's good. But if it doesn't, STOP! unscrew the screw on the top of the fill adapter and press the chuck into the tire valve again to release the pressure.
3. Once the gauge reads the desired pressure, you are done filling it.
Once you get the hang of it, you can do it really fast.
