I own 6 leupold scopes, 3.5-10x40, 4.5-14x40AO, 6.5-20x50LR,M4 8.5-25x50, M4 16x, M4 10x. I have used the 4.5-14 on everything from coyotes at 30 yards to pdogs at over 700, It is the most versatile scope I own. Mine is the older version, get the new one with the side focus. Unless your shooting in the early morning or late evening 40 mm will be preferable to keep a rock solid cheek weld.
Excellent choice on the rifle, Happy hunting!