MontanaMarine,
If I read your post correctly, such a bullet is deflected 21.6" in a 10mph crosswind.
What happens if the crosswind is 5mph or 15mph? Yes, I know you can measure it from where you are shooting, but what is the effective wind over the 600 yards, where it may be swirling around, there may be a gully, etc. What if it changes just as you shoot?
Such a condition causes a 10" miss horizontally. If your basic hold is off by 6" you get 16" and a wounded deer.
