ORIGINAL: Roskoe
You are about the same size as my 14 year old son. He shot a 7MM-08 last year with no problems. 30/06 was a little too much. This year, I got him a 7 Rem Mag - loaded the 168 gr. Berger VLD bullet to only 2730 fps (starting load). He said it kicked about the same as the 7MM-08. I plan to increase the horsepower of the loads as he gets bigger. I would rate his tolerance for recoil as about average.
I don't think I'd want to get a 7mm Rem Mag, 'cause it's pretty much going to have little or no advantage over my .308 in comparison to other calibers.
Part of the reason that I want a bigger gun is that I want to have the capability of making 300 yard shots without having my bullet drop 4" or something like my .308 does.