@Tidus56 and
@Creedmoor shooter : 7mm Mag is pretty dang hard to beat, but I don't see any factory rifles that have enough twist for my taste. I looked at some factory ammo options, and 2200 fps at 400 yds is not a sure thing, although there's some get you there with some room to spare (e.g. Barnes LRX). Even reloading, with a 1:9.5 twist, you can't take advantage of the mid-weight Hammer Hunters.
@WWP2012 regarding paper and steel, it would just be some fun plinking (and wind practice) in a big wheat field. 1 MOA is sufficient, which I think most decent factory rifles will do. Without me to motivate him, I doubt he'll be doing it otherwise, so I'd almost certainly be hand loading all his target ammo.
Regarding 6.5 PRC, I consider it to be the "bare minimum" to achieve #1, as we're both "more than enough gun" kinda guys. With copper bullets, I just don't like the energy levels at 400 yds for elk. By no means saying it's not doable, I just like to see 2200 fps and 1500 ftlbs or more. Also, I only see 2 factory options in copper (Nosler E-Tip 120 gr, and Barnes 127 LRX). Definitely a contender though.
@memtb I think 338WM is a bit more than needed. He already has an old Winchester 670 in 300WM. It shoots OK, but he's looking for something a little more modern, and is excited about just "getting a new rifle".
@Shane Lindsey No doubt the old 06 will get her done, but IMO, the 7mm will do everything it will and more. Economy and rifle/ammo options are unparalleled though.