this is a very hard rank to get there are many things you need to do to reach this rank the first thing i will name is concistency i know you dnt lose your rank by dnt playing but if you really want that rank you need to commit.
The next thing i would say is to have over a 200 kd this plays a fairly big factor in your rank a good way to do this is to start on round 20 and pack a punch your pistol and go up to the jug room and not open the door untill it gets crazy.
the amount of kills u want to get this rank is getting 30 000+ kills you dont see many people with shotguns with only 5000 kills.
and my last thing i wanna say is get to high rounds but that doesnt mean like over 50 id say atleast 25 to 40 that is what i learn. this may not work for all of you but i hope i helped if anyone needs any help in person pm your gamertag..