So I punched in my info on this "Strelok" app, and it was pretty dead on nuts on target with elevation from 600 out to 800 yards, wow!
I was shooting pulled rounds so it was sh*t going out further pass 800 yards.
It was my first time messing with this stuff, but I now see the actual benefits of having one of these ballistic calculators.

.. but I've yet to try it on 10 or 20 yard increments