Weapons Rank system?

For KF2 it would be nice to incorporate a weapons rank system within the 1-6 or how ever many levels per a perk. For example A level 1 sharp shooter can buy these, 5-6 guns, For a higher caliber weapon it would require a higher level. It would also make more sense, as the player levels up his perks he gains more experience, and with that experience he is able to properly use better weapons, his expertise would increase in a sense and he'll be able to operate those guns. It would also add more taste to the game.