ok....umm.....since I cannot trust the dictator, and if I don't do as he says, he'll flood the chamber with gas, killing us all.
I'd fire the gun until it has no ammo, purposefully missing anyone, although I'm sure the ricochet would clip someone, and then I'd be like "Hey, I need a new clip of ammo" and then I'd shoot the guy with the new ammo (if possible), and use my super powers of telepathic mind control to make the dictator let all of the children go, then procede to make a made-for-television movie no doubt played on the lifetime channel and then make a million dollars from my new-founded mutant powers.