K-22hornet,
I think your parallax idea is very likely the solution. Unless it is really windy, 1/2” groups at 100 yards shouldn’t turn into 2”groups at 200 yards.
Honestly, I’m really happy with 2 1/2” groups at 200 yards under “field conditions” while hunting coyotes. I would be ecstatic if I could hit within 1MOA 95% of the time while sitting in hunting conditions with shooting sticks or other rest.
