Although your initial reaction may be one of disbelief with regards to the types of gas used in gas powered airsoft guns, it is important to consider. There are many high quality gas airsoft guns out there, but if you use the wrong type of gas to power them on a consistent basis, you may find that your gun will wear out sooner than you expected. Let's just go over a few things about the different types of gas and the respective consequences you may face:

Propane and Butane Gas

Use standard propane or butane gas in your airsoft pistol can cause degradation over time. Although cheaper to buy and implement, it doesn't make much sense to use this type of gas in a gas powered airsoft gun, because the gun itself is usually quite expense, seeing as how gas airsoft guns are more powerful and more life-like than electric or spring powered guns.

HFC 134A Gas

This type of gas is rated for use in Japanese manufactured airsoft guns. It is kind of like a middle-of-the-road gas for economy buyers. These gas gun are cheaper than the more pricey US brands, but are a good price point buy. The HFC 134A gas is not quite as powerful as the HFC 22 gas, but again, it is a good compromise between price and results.

HFC 22 "Green Gas"

This is the better quality, higher power gas that is offered for airsoft guns today. It not only prolongs the life of the gun, but you can usually achieve much higher feet per second (FPS) in your gun than with other gas types. Also, manufacturers are putting out smaller, higher pressurized canisters to provide several recharges to your gas airsoft gun, while being small enough to ride in an accessory belt or pouch. With just a few dollar difference per canister, this seems to be the better choice.

So there you have it, the main stream options for use with your gas airsoft gun. Remember to check with your retailer / manufacturer for the recommended gas to use with your particular model of gas gun. While green gas may be the better of the options, it is still the best idea to check it out before purchase. These types of gas are usually easy to load into your airsoft gun, but make sure to check the directions to see if there are any specific instructions or warnings before you improperly use the airsoft gas. One last thought, make sure the clip is detached from the gun you are loading, because you might inadvertently fire the gun if you attempt to reload the gas while the clip is still in the gun itself.