No. The base of the guns are different and it is impossible to change it into a quality CO2.
No. even though some spring guns have great range, co2 allows you to fire more then once before reloading.
Neither
Well no a Co2 cun justs uses compresed Co2 intead of a spring or a batery Co2 if fairly cheap and are easy to use
An air-soft gun that is powered by CO2 or green or red gas instead of a spring or a battery.
No
No company makes a spring action galil airsoft gun currently.
You can't without some experience in metalwork.
It depends on the make/model of the gun, and the power source (AEG, CO2, green gas, as spring ones require to be cocked after each shot.)
Keep it clean and get a stronger spring.
go for the m14, unless its cheap looking.
yes
No you do not need to put air in an airsoft gun. These guns are either spring powered where you must cock the gun before you shoot it, electric powered which are automatic and require batteries, or CO2 powered which requires a CO2 cartridge. This CO2 is not expensive and a pack of 40 CO2 cartridges costs only 20-25 dollars. the guns that require CO2 are not as common as the other forms of airsoft guns, although they are more powerful. In general, if you buy an airsoft gun, you do not need to put any air into it.