I heard many conflicting information on this. Some say it’s a 300 yard affair max. Others say twice that is doable. I know the Marines qualified at 500 yards (meters?) with their M16s BUT had spotters and wind flags correct me if I’m wrong? How realistically possible is it for a solo shooter in a field type situation, with an iron-sighted 20” AR-15, to hit a man-sized target at 500 yards assuming the rifle is capable of grouping well and the shooter is skilled? What goes in to judging windage at such a long range and is it even realistically possible without range flags and spotters? Thanks!