RE: Youth rifle!
Of all the short actions the 308 has the most knockdown power. It'll do for elk, but has a LIMITED range. They say 1200 ft/lbs for whitetails, so I'd guess at least 2000 ft/lbs for elk. Useing that the 308 would be good out to @200yds. I'm sure someone who's shot this caliber for years and knows it inside and out can stretch that but none of the short actions are ideal for elk. A 30-06 would be better there are so many different loads for it that you can buy lower velocity(hence lower recoil) loads for deer, then get some premium loads for elk.