Since I want to eliminate as much human error as possible during initial sight-in/load development, I use an adjustable rest with sandbags.
Once I am satisfied with the rifle/load's ability, then I shift to field positions to check if any differences are evident.
This also gives me a chance to decide how long a shot I feel confident with when actually hunting.
Since I always carry with a sling, and do not use a bipod, the "tight sling" position is important to me.
Lots of practice is always a good idea.
When practicing, I determine my maximum range as the distance that I can no longer keep all my shots in an 8 inch circle.
Obviously, the range varies, depending on the position used.
Regards, Eagleye.