Originally Posted by Motorexskygtr32
The fastest way I did to earn XP rank is Chapter 1: Mission 4: DitchSlap on Inferno. I was Rank 4, and had the bots with me. Killed Hectors, Ants, and Spiders before the tunnel...took me about 10-15K in that first part. Now, I killed two bots before blew the tunnel up. I went in and bombed 2 anthills and leave one anthill alive to keep ants respawn. I went back in the beginning of the tunnel where the water flown at, set up the plasma turret and using Homing Missiles to shoot the ants. The problem here is the max XP is 65,550. It will not go up anymore. I don't know if it is this specific level or all levels. After it stopped 65,550, I went back to the bots to revived them and finished it. It took me less than 30 minutes to get that 65K XP.
I haven't test out on any missions to farm for more XP except Chapter 1: Mission 4: Ditchslap so feel free to post your XP guides!
I am going to have to pull your card and call bullshit on this one. There is no way you made it through this board with a level 4 character on inferno.