Step 1: Remove it from medium fire rate auto rifles. There is just no way for it to work here.
Step 2: Increase the fire rate on focused fire high impact autos from 6 frames between shots to 5 frames between shots (300rpm -> 360rpm).
This fire rate is what you get when you tap fire it, and when doing so optimally it becomes a great perk.
Step 3: Increase the range when using it on a max fire rate auto. Max fire rate autos with focused fire essentially become mid fire rate autos with a huge magazine.
Since mid fire rates kill slower than max fire rates, giving them more range combined with the huge mag size would be enough to make it viable.
-
Or just increase damage, problem solved