The last challenge is get 30 kills in BTB.
It’s only for Mark 7 until cross core starts.
Remember when challenges used to be hard?
I hate to admit it but that took longer than it should have.
I really don’t play BTB, and I’m not super familiar with the weapon spawns.
I got a ton of assists though (at least two wingman medals).
BTB can be pretty random at times. You could get an ordinace drop of a power weapon for find yourself in a tank or wasp. In those cases it’s possible to get the 30 kills in 1 game.