This post is to request some guidance: I live at sea level and will be going on a hunt at 10-12,000 ft and temps of approx 15 degrees F. I am currently zeroed in at 3.0" high at 100 yds for a 300 yd zero (30 cal, 3300fps, BC of 404, 168 gr Barnes TSX)with anticipated shots usually in the 300 -...