This bloom would be based on range, and would ALWAYS be active instead of just while shooting.
What i would do to bloom is have it so every gun had a different amount of bloom based on how far away they are shooting. That way the closer you are with a close ranged weapon the more accurate you are, and the further you are with a close ranged weapon the less accurate you are.
THE SAME WOULD GO FOR EVERYTHING
Mid Ranged Guns:
Super close is less accurate
Super far away is less accurate
Long Ranged Weapons:
Far to Super Far are perfectly bloomless
Mid To Close gets bloom