CO2 and compressed air are two types of air sources for paintball guns. These air sources are available in metal cylinders that attach to the rear of your paintball gun. These two air sources can be filled at virtually any paintball field and store. While they both serve the same purpose, each of these gasses differ significantly in price, performance and popularity.
HPA, or high pressure compressed air, is a new air source for paintball guns. This air requires the use of a compressed air tank, which can be expensive. HPA contains the air that is present in the atmosphere, only it is compressed to between 3,000 and 4,500 psi, depending on the type of tank used.
CO2 has been a common source of propulsion for paintballs since the game was invented. CO2, which is carbon dioxide, is put into aluminum tanks that are designated for CO2 use only. CO2 tanks are very cheap at around $20. They are also available at more stores than compressed air tanks.
HPA significantly outperforms CO2. CO2 can be quite inconsistent and the pressure that is released from the tank increases with warm weather. HPA is always released from the tank at a consistent pressure. More consistent air sources allow the paintball gun to shoot more accurately. Consistency also prevents paintballs from breaking inside of the gun.
Gun Wear and Tear
CO2 can cause serious wear and tear to the internals of a paintball gun. CO2, when released from the tank, can be quite cold, which can have a negative effect on the rubber seals of the gun. Also, the inconsistent nature of CO2 puts added wear on the moving parts. HPA does not adversely affect the internal seals and parts of the paintball gun.
Certain paintball guns, specifically higher-end guns, require the use of HPA. CO2 will damage the delicate internals of these guns, resulting in poor accuracy and even the failure to fire. Also, faster-shooting guns will not be able to maintain a high rate of fire with CO2 because of its inability to provide consistency. Many gun manufacturers will make a notation of which type of air source should be used.
Whenever using CO2 as an air source, it is important to have an expansion chamber present on the gun. Expansion chambers provide a place for CO2 to expand into a gas form. Without one of these parts, a portion of the CO2 will remain in a liquid form. Expansion chambers typically replace the foregrip of a paintball gun and are between the CO2 tank and the body of the gun.