Single-handedly kill a Tank.
30 (G)

best to do this with 4 people and best on No Mercy.  k get to the end so the helicopter is there have the 3 ppl who don't want it go down near the choper Key don't shoot the tank, next have the person who wants it get in the choper.  (Might want to have a sniper) Now shoot the tank and kill it. as long as u r in the chopter and back far enough, u wont get hurt.  It worked for me. Don't give up.