[L473ncy]

CO2 is guaranteed to shoot too hot for indoors and if you're playing outdoors and need a sidearm for below MED definitely not able to use it. CO2 has higher pressures straight up. Because of those higher pressures it might put more stress on the gun. However it does have higher FPS and more shots per mag (probably about 3 mags worth before needing to change the canister), it also doesn't really suffer from cool down effect as much.