Missiles randomly spawning well inside enemies maximum range

I'm currently testing my KKV missiles against solar lances to see how thin I can get the armor before it becomes a problem, but often they'll spawn anywhere from 13-25 km away instead of the usual just outside the 50 km maximum range. I'll update with any info I can on what causes it, I think it might be the angle of approach on the orbital map but I'm not sure.