As you may know underkill was a perk in call of duty black ops 4 and I hope that Infinity Ward will add this perk to Call of Duty: Modern Warfare (2019). In my opinion this perk was extremely fun to use for challenges or leveling up secondary weapons. As a sort of secondary weapon connoisseur (Completionist Akimbo deagles) I am trying to get completionist for as many secondaries as possible and the underkill perk would be invaluable as a grinding tool especially on maps such as shipment where you don't really get time to switch to your secondary. I am sure that there are many people who also have this issue and would be ecstatic if they could add this small feature to the game. It is also very obvious that this is already possible in the games code with modes such as All or Nothing having 2 secondaries, Gunfight sometimes having only secondaries and One in the Chamber also having only secondary weapons. It would hardly affect anything negatively, as I have already stated this should be added to the game as soon as possible. All I am asking is for Infinity Ward to add a fun simple perk to the game.