God call, long path!
The .257 Roberst, dubbed by someone "the most useful cartridge" (I think he was referring to North America) is an incredible little number. With the 120-gr bullet, I wouldn't hesitate taking it against ANY hoofed animal in NA (except for perhaps bison). By the way, the parent case of the .257 is the 7x57!
Dr. Bob, as much as I am reticent to disagree with a DR (I am only an MBA), you can get brand-new, out-of-the-box hunting rifles in 7x57 made here in the good ole USofA! An example? The wonderful little Ruger N.1, which comes both in the light sporter version and in the elegant "international", Mannlicher-stocked fashion.
Ruger also offers their M77 bolt rifle in that chambering for a retail setback of a little over $400. And should you opt for a time-honored surplus and you are picky about accuracy, Mauserwerke made an excellent model in 7X57 for the Spanish Gov't, which can be picked up at a show in "mint" condition for a couple hundreds. I defy anyone to a 100-yrd postal match using (them) ANY out-of the box US made sporting rifle versus (me) this Mauser!
Lastly, there are a host of excellent European rifles in this caliber. Depending on how much you are willing to invest on the young sapling's first rifle, you can go (in descending order) from a Steyr-Mannlicher to a Euromark with everything in between (a copy of the Guns and Ammo 2,000 edition buyer's guide) will tell you all you want to know).
Good call on the .44 magnum! I don't know how important "flat-shooting" is to you, but Ruger (hmmmmm.... I seem to pick that firm a lot
) makes an awesome little bolt-action number in 44, which would help the young buck get use to the feel of the "turnbolt" while having great killing power out to 125 yds with neglegible recoil.
Let us know what you finally opted for!!!!