Re: how much power
Nightforce optics are clear enough that 22x is very very effective at 1000 yards without the distortion from mirage ect... of a 40+ power scope. At 600 yards I can see bullet holes on a paper plate (.30 cal) with the sun to my back. Hope that helps.
Long range shooting is a process that ends with a result. Once you start to focus on the result (how bad your last shot was, how big the group is going to be, what your buck will score, what your match score is, what place you are in...) then you loose the capacity to focus on the process.