out to 300 yards, go with a .308 or 30-06. there limits can be pushed out slightly further, maybe 400 yards, but then if shots are expected to be at 400yards, you might want to consider getting closer to the deer,
as for the rifle, any will do really, savage, remington, ruger, winchester, tikka, etc.. but not really in any particular order

propmahn
you can never have too many guns