I hunted last fall with a couple guys who had the leupold 6.5-20. They had leupold install target turrets on them. They also had leupolds cutom shop calculate and etch the ballistics from there loads on the turrets. So they could range the shot, dial the turret for yardage and hold dead on. They were comfortable shooting 500yds. with their setups. Not to say that they would encourage that, but they had put in the time and work to do so if absolutely need be. I love the leupolds. I own a couple zeiss and they are nice also, but leupold has won the bulk of my business through their service. The more I hunt the more I like the high powered scopes. I'd go with the 6.5-20x50 or the 6.5-20x40 LR 30mm tube, or the 4.5-14 in either config.
Just my two cents.
A week from now I'll be in WY antelope hunting with my .257 wby accumark topped with a 8.5-25x50mm LR leupold. Its almost like cheating. I can not wait.