Sorting out a gun pointed 90 degrees to the free stream velocity is what turrets do every day they are used. The Comanche had a good airspeed system in the blades that read speed and azimuth, and so did the Mi28. I would imagine the KA-50 could/should also have that feature, since they didn't even bother to turret the big gun.
The KA-50 is really not used as a helicopter in the doctrine that employs it, it is more like a stol A-10, conducting swooping run-in attacks from altitude, and not NOE. The single pilot would get lost alot if the thing were brought down to NOE tactics.
The Mi-28 was the KA-50's competitor, and it is more classic in design, similar to the Apache (but without its excellent pilotage and targeting systems).