Originally Posted by SheriffMike
plus C02 is heavy. and nobody likes extra weight.
when you fill a C02 tank you add a whole extra pound plus.
actually, c02 is a far better gas if you think about wight.
per unit of mass (ounce in this case), c02 has far more energy than a comparable ounce of air at 4500 PSI.
this is becuase co2 goes though a phase change from the tank to the gun, from liquid to gas. and this phase change contains ALOT of energy, and so an ounce of liquid co2 has alot more energy in it than an ounce of 4500 PSI air.
its easy to see how this is true. i used to use a 68/4500 on a cocker of mine. i used to get about 1700 shots per fill on it. fairly good right? with a 20 ounce co2, i could get over 2200 shots.