Well to add my bit on this.
IIRC the Russian army purchased 20+ Ka-50s and some of these saw limited combat in Chechnya. The Ka-50 is mainly for battlefield FAC but with those weapons I could see it doing CAS as well.
As for the R-73s, The KA-50 was fitted out with these for display purposes only, there has never been a live firing of the R-73 from the Ka-50 and AFAIK it does not have the aproppraite systems yet to fire the R-73s installed but as GG has said the Vkhir is A2A capable against IIRC targets below 800Km/h so this can be used for limited protection against any choppers or slow aircraft so whats the point of 2 R-73s taking up the space that 12 Vkhirs can utilise.