I've gotten A rank on the Gun Emplacement mission every time, and I've gotten the mission time to under 30 seconds and I still don't get the bonus. What's wrong?

I can't promise this will work, but you might have to do the mission without a consort. Also, it may be this is one of those missions you can accept at the end of another mission, if I recall right. Try accepting it after doing the first mission so you do them together, and try doing it solo also, perhaps it can only be got one of these ways. Best of luck .

Do remove gun emplacements in under two minutes, accept the next mission regardless of your consort, if you succeed the next mission you will get it.