Multiple bullets per gun
Anyway, on the topic of "multiple virtual bullets", I have tried something like this before, except I took it to the extreme. What I did in some versions of RougeDC is equivalent to what you suggest except with infinite differently weighted bullets. It integrated the result across the angles.
My experience is that this method was much faster adapting than the conventional single bullet approach. It was very useful against surfers that you need to adapt quickly against (i.e. swapping targeting systems when they've learned one too well). The disadvantage, is that it converges to a less accurate result.