I have a BSA Platinum 10-50x60 the big brother to the nikko big 60.
I range & shoot on full mag sitting. kneeling & Standing I rangefind on full mag & drop to 30mag to shoot.

sometimes thou, like some of the others above in any position if the targets hard to aquaire for any reason I will drop to lower mag to get the target. I'd probably shoot on lower mags if I had either a ladder reticule of Mill Dot in stead of the target dot/

Hope it helps?

Darren