Originally Posted by LouTenit Dan
Just wanted to add this..Im pretty sure you get more XP when you come in 1st too..So 1st place + Double XP+ Fast Track gets you 17800(for me atleast) then I noticed once you replay the mission you start getting less...Something round 16xxx and just goes down from there
They raised the cap on the amount of XP you can get in one game. Nothing has changed other than that. You most likely received less XP after your "first" match because you completed it too quickly; you get maximum XP once the match has reached 8m30s. You must also start the match with 3-4 players to retain the default difficulty as well as having at least 8 kills by the time it ends.
Your ranking or the amount of deaths you have have no bearing on how much XP you receive.