50-90 paper?

[Kurt]

It's not only light, it's also air density as the day progresses and the ground warms up.
I seen elevation changes, especially at the Quigley shoots or Alliance NE. were my morning sight settings will change a much as 3 MOA sometimes especially when the ground is wet from the morning dew and the sun starts to evaporate the moisture changing the elevations.
What is really frustrating to me is when I can cover 5-10 shots with a silver dollar one day and the next time out with the same loads loaded at the same time the groups are patterns.