RE: Good long-range deer calibers.
For a youngster buying a first rifle -- a rifle that is intended to be used for many different game on many different kind of hunts -- it is difficult to beat the .30-06. Remember the context is flexibility here. A standard bolt action is probably the way to go.
If someone is interested in long range shooting, that is specialized shooting calling for a specialized rifle. In my opinion, you are going to have to give up something to get this special behavior -- a heavier recoiling cartridge, a louder muzzle blast, a more expensive commercial load, maybe even a heavier rifle to shoot accurately at long range.
A lot of talk is done about long range hunting, but in fact most game is taken at pretty short range. Additionally, most hunters spend precious little time shooting for practice and hence should not be blasting away at long range. You aren't born shooting well and the skill does not remain tuned and conditioned if you aren't practicing a lot. I have read articles written by guides about the skills of hunters, and it was not encouraging. My memory was that the articles agree that most hunters cannot reliably hit in the vitals at 200 yards -- that means less than 50% (5 out of 10) can hit in the vitals at 200 yards, maybe less than 10%, I don't remember the figures I read. Anyway, the statistics aren't good for the average Joe Hunter to be taking 300 yard shots. I would hate to say what percentage of my shots would hit a paper plate at 300 yards from a field position, an experiment I have not had the occasion to make.