I have been loking around for some data on CO2 to resolve several questions that have come up here.
Q) Why do I lose pellet velocity when I use the gun in cold weather?
A) A 40 F (25 C) drop in temperature will reduce gas pressure by about half.
CO2 pressure (Pounds per square inch) at some temperatures (degees F):
- 969 PSI at 80 F
- 853 PSI at 70 F (about 25 deg C)
- 747 PSI at 60 F
- 567 PSI at 40 F
- 491 PSI at 30 F (about 0 deg C)
- 422 PSI at 20 F
- 306 PSI at 0 F
Link:
http://www.airsmith.com/co2n2/co2graph.htm
Q) What about mild heating of the CO2 cartridge in cold weather.
A) Some feel this is unsafe, but a reasonable person should be able to do it. Airsmith (link above) suggest the possibility of the cart/tank safety valve rupturing. I plan to try a very small heater to give a little temp rise and will report on my findings. (I'm thinking of a 10-20 F temp boost.)
Q) What about using other gases to boost pressure.
A) I had thought about O2 breifly, but it is too high of pressure. See the link below of a vehicle blow apart by a large O2 tank, when parked in the Sun for a short time!
Link:
http://www.wetcanvas.com/forums/html_archive/topic/139084-1.html