For load development, I employ a couple of different methods but in all cases I use the max magnification. None of my scopes are more that 16 power. More importantly for me (hunting or competition) I try to remove as many variables as possible: Shoot on a clear day with low wind; use a shooting bench / lead sled; in my case, try to minimize heat...I put my ammo on ice. I mean its 108 degrees out in the summer.
