Let him handle examples of both rifles and make the decision on which fits him the best. The cartridge difference will be negligible for a novice shooter as he will have no business shooting at game past about 150 yds for a long while anyway. Get him a good fixed 4X scope with a simple duplex reticle. Keep the whole rig as simple as you can. If he graduates to being a rifle loony, he will want other rifles in the future anyway. Fit to shooter is the most important factor.
Probably the best advice yet.
