GTA
All Springer/NP/PCP Air Gun Discussion General => "Bob and Lloyds Workshop" => Topic started by: oldpro on June 15, 2022, 05:36:00 PM
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Simply put does CO2 at the same pressure as HPA make more power?
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Well "simply put", CO2 is denser than air, so I would assume that it could deliver more energy at the same pressures. However, I didn't sleep at Holiday Inn last night, and I thought I made a mistake once, but I was mistaken. ;D
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I think that the co2 gas is heavier than air, so more energy will be used just pushing the gas through the barrel.
But, I really don't know.
Hunter
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Nope. air delivers more FPE than CO2, in the same gun at the same pressure.... CO2 molecules are about 50% heavier than air, and for the same reason that Helium delivers more FPE than air (because it is lighter), CO2 molecules rob more of the available energy to accelerate them than the same volume of air would.... Simply put, a higher percentage of the potentially available power (pressure times bore area times barrel length) is used to accelerate the gas, so less is available to accelerate the projectile....
Bob
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Nope. air delivers more FPE than CO2, in the same gun at the same pressure.... CO2 molecules are about 50% heavier than air, and for the same reason that Helium delivers more FPE than air (because it is lighter), CO2 molecules rob more of the available energy to accelerate them than the same volume of air would.... Simply put, a higher percentage of the potentially available power (pressure times bore area times barrel length) is used to accelerate the gas, so less is available to accelerate the projectile....
Bob
Dang, I knew I should have stayed at that Holiday Inn last night. ;D
Bob, are you sure Helium doesn't deliver more power cause it's smaller and squeezes through all those tiny orifices, and makes it around all of those bends and turns so much easier than air? ;D Therefore there has to be less drag losses than with FAT air molecules. :o ;D 8)
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In an informal A/B test I did a few years ago, the same gun produced about 50% more energy with air than it did with CO2.
The state of tune for both was the velocity knee for CO2. When I refilled with air, it produced a bell curve centered somewhere around 800-900psi which made me think it was a pretty fair comparison.