Originally Posted by Slim
I'd just like to say that the best advice I could give anyone who is looking for technical answers is to do as much searching and reading before asking any questions as possible. Unfortunately, searching for answers here on MCB might not give you the help you really need. I've noticed quite a few folks here giving out tips and advice on CO2 efficiency who obviously haven't bothered to familiarize themselves with the basic properties and principals of CO2. This well-intentioned advice is actually costing other players money on mods that may actually cost them efficiency. The bottom line is, it's simply impossible to discuss CO2 efficiency without understanding how CO2 operates.
Without getting into any advanced physics here, the following will provide some basic, basic, basic information on the principals and properties of CO2.
From PyramidAir.com (please note that Pyramid Air is discussing the specific effects of CO2 in a pellet gun as opposed to a paintball gun. As the two are almost identical in operation, the PRINCIPAL is fully applicable to any discussion we have regarding CO2 efficiency)...
So, what have we learned here?
1) CO2 can exist as a gas, liquid or solid. CO2 gas turns into a liquid when it is compressed and cooled. It will sublimate ("boils", "flashes") back into a gas (or solid) when it reaches a pressure of just over 60 PSI, and/or temperatures over 70°F.
2) CO2 pressure is determined by temperature, not by mechanical compression.
When Scharfschutze91 states that he's getting "around 40 - 45 shots off of a 12 gram shooting around 290-300 fps", is it because he's using a Freak-bored barrel and a red main spring? Or is it because he lives in Miami, Florida and was shooting in 90° heat with 80% humidity?
If Pauly took Scharfschutze91's Phantom from Miami to his house in Long Island New York today, and shoots it in 41° weather with 30% humidity, do you think he'll get 40 shots off of a 12-gram?
No, because the cold temperature in NY will decrease the overall pressure (i.e. efficiency) of the 12-gram. While the mods in Scharfschutze91's Phantom may garner an extra shot or two, it's the temperature that is making the real difference. Also, the temps and lower humidity in NY will keep the paint from swelling up slightly, which may allow "blow-by" even with inserts or a bore-matched barrel.
If Pauly waited till the dead of Summer when it's 90° out with high humidity on Long Island, then I'm sure he would see similar results as Scharfschutze91, but at 90°, even an unmodified Phantom will see a noticeable increase in efficiency. Why? Because CO2 pressure is determined by temperature.
3) At 70° F, the pressure of an unopened 12-gram CO2 Cartridge is 852.8 psi.
4) CO2 is a cryogenic gas which dramatically cools down the valve system in the Phantom. Therefore, the pressure will drop dramatically when a series of shots are fired in rapid succession.
Add all the efficiency mods you want. If you don't pause between shots to let the gun warm up, then the mods will have little effect.
Now that we've gone over the most basic principals and properties of CO2, we can discuss Phantom efficiency with a far better understanding of how potential mods may, or may not work.