These are some numbers on air-to-air missile usage I accumulated on the 51st server during August, September and October 2010.
Shown here are the percentages of the missiles that killed (blue), hit (green) or missed (red) their target. At the right it shows how many missiles of each type were fired. During this three month period over 20000 air-to-air missiles were fired.
This is an update of the plot I showed earlier, but now using much more data.
In general, I think one can conclude the following:
R-73's are the best air-to-air missiles, having over 50% chance of hitting their target, and about a 1 in 3 chance of killing it.
Of the long-range radar missiles, they are ordered: R-77, AIM-120C, AIM-120B, AIM-7, R-27ER, R-27EM (note the small numbers on AIM-7 though).
AIM-120C's are only slightly better than AIM-120B's.
AIM-7's are most lethal when hitting.
R-27ER's are the same as R-27EM's.