Its possible that your heavier arrow will shoot FLATTER out at 30 yards
I disagree with that...........At 30 yds the lighter is STILL going faster and hitting the target first.
When shot out of the same bow - the lighter arrow will allways hit the target first at all reasonable hunting distances.
They both drop at the same rate of speed - all arrows drop at the same rate of speed - the first to hit just has less time to drop. It takes a long distance for the heavier arrow to catch up and make up for all the lost time.............