They both have pros and cons.
CO2
Pros
Works better in cold weather.
Cheaper than green gas (Depending on where you buy it).
More common.
Cons
It does not lube your airsoft gun which means that you have to have to clean your gun more.
It has a nasty odor.
It is tougher on your gun
Green Gas
Pros
Green Gas is just propane with silicon oil mixed in, so if you have a propane adapter and silicone oil you can just use propane which is cheaper than both CO2 and Green Gas.
Premixed with silicone oil
Your gun will require less maintenance
Not as tough on your airsoft gun
Cons
Green gas is more expensive
Harder to find if you don't buy online
Propane
Pros
Very cheap
Easy to find
Efficient
Cons
You have to mix silcone oil in your self
You need a propane adapter
Overall propane gives you the most bang for your buck, and you will save a lot of money if you get a green gas gun and adapt it to use propane (super easy to do).
It depends on what type of gun you are using. Refer to the manual. I would say that Green gas would be better than CO2 because it keeps your gun in better condition, but use CO2 if your gun suggests that you should use HFC 134a.
No their about the same
No.
It all depends on the strength of the spring airsoft rifle. If your refering to pistols (I will assume you are), I prefer a co2 or green-gas pistol over a springer anyday. In the big picture, springers are regarded as cheap and useless. Although the fps may be better than that of the gas, it's range (and the fact that you need to cock spring guns after every shot,) it is usually better to save up your cash and buy a good gas pistol. However, even I need to admit that some springers (i.e. quality snipers {runs you about 90-110 American dollars}) are way better than their co2 and green-gas counterparts.
The true gas that causes it is CO2
that depends on the magazine and gun in my green gas pistol a short 3-4 second fill up allows about 20 shots to be fired. A Co2 canister allows about 100 shots to be fired. But Co2 should only be used in guns that say Co2 ready and the same goes for green gas. An advantage for green gas is that the guns are usually cheaper and an advantage for co2 is the cartriges can be bought almost anywhere while as the green gas must be ordered online.
No, Co2 airsoft guns run off disposable 12 gram cartridges, whereas green gas guns have internal storage and are refilled by propane tanks. Actually there are now dual use guns and adapters to use CO2 to fill green gas guns .
gbb and gnbb in other word gas blow back and gas non blow back airsoft guns are more powerful than a co2 gun which fps for a co2 gun resides around 200 fps roughly give or take and a gas airsoft gun starts usually around 250-300 fps
Green gas is basically propane with silicone oil in it. So it's better than just plain propane.
Carbon dioxide. CO2
Carbon dioxide (CO2).
carbon dioxide CO2