I have a kwc co2 uzi, and it won't finish a whole magazine even on semi-auto. Also the magazines are extremely heavy, and you would need a lot of them to keep up with AEG's. I even converted mine to run on top gas, and it still won't empty a whole magazine. The coold down effect is horrible on this gun. Its cool to play around with, but won't do for skirmishing. I don't have a chrono, so I can't give exact numbers on velocity. However, I fired it at a sturdy piece of card board from about 15 feet away and it punched through that and dented the drywall five or six feet away on the other side. Its got a lot of punch to it.