specialist with the type 95 (if you know how to use it) or the acr. party up with some friends and go to the game mode your best at (not your favorite one) and run around to the spot(s) where all of the campers go.
if any one agrees or has something to add feel free to express what you think.
The type has got to be the best gun to put yourself in a situation to get a MOAB, its a 1 trigger pull, just slap on silencer and red dot, and have stalker. Everything is going for you at that point, Just ADS all game, and take it slow.
I got my first moab by staying in the area where the tunnel is on the map hardhat. That is mostly where everyone runs to so it is easy to kill people. This is in FFA by the way.