Ok, I gave you some crap about that; I totally misstyped. My size 2 sensor has 300k range, so now I need a size 6 to see the missiles at that high enough range. As said, I've yet to encounter missiles bigger than size 6. And I had a size 4 that for some weird reason used Active strength 14 or something, so that explains a lot. Sorry for confusing you.
Btw, the original suggestion of a narrowband active only seeing a small range of HS, couldn't you use that for missiles?
Which would be easily explained with the missile seeing more, but not reacting to it.