Need a little help deciding? Places to fill a CO2 can be found virtually anywhere, and the tanks themselves are cheaper. CO2 is dependent on weather, so your shots will be less consistent if it's cold or hot, or when firing rapidly.
HPA, also called compressed or high-pressure air, holds air at a high pressure, and the equipment for refilling HPA may require specialty shops like places you can fill scuba tanks. HPA tanks are also more expensive. However, HPA is more consistent in all weather conditions, and is not affected by rapid firing. Further, HPA will not damage your gun internals; CO2 tends to be harder on markers, and is completely incompatible with some higher-end guns- be sure to check your manual or ask our experts at 800-875-4547.
If you think you're in the game for the long-haul, an HPA tank is probably a sound investment, and aluminum HPA tanks are moderately priced if a fiber-wrap tank makes your eyes spin.
Still need more? Check out our guide Explaining the Differences Between CO2 and Compressed Air