Not meant as a flame but, we have a guy in our clan who would say, "Spam bullet like a n00b, die like a n00b."
Seriously tho, any time I hear "emptied my clip and he didn't go down" I have to wonder just what the accuracy was on those shots...ya know? I have definitely been in the same situation myself, wondering if this uber-soldier was cheating...but as an admin I haven't seen an actual hack which allows you to not take damage on a ranked server. Please, correct me if I'm wrong...(But Don't post info on the hack...PLEASE)
My suggestion would be search for low ping servers and focus on burst fire...