I bought my son a Rem 700 7mm-08 when he was 6yrs old. He is now 10 and has 8 Texas whitetails and several hogs to his name.
I have been loading it with reduced 120 grain ballistic tip loads and will slowly work him up to full strength loads as he grows.
I had the original tupperware SPS stock cut down to 12.5" when he first started shooting but have since dropped it into a B&C stock that is 13" LOP and he shoots it just fine.
Good Luck!
This would be my suggestion as well. I'd also throw it out there that a Rem700 Mountain Rifle in 7-08 is a really light and easy package for a kid to handle. My daughter shot mine quite a bit and enjoyed it. Very light up front, so much easier on little arms. Load 120 NBT's at 2600-2800 fps to start with.... as he gets older, the sky is the limit with a 7-08...
