Both of my boys started with the Remington in .243 when they were about 7.

Then when they were about 10 they moved to a Dakota Youth Model in .308. That is a more expensive rifle than the rifles made by the big companies, but what a slick little package it is! It's about 7/8 scale in everything except the chamber. Dakota offers a deal where you can trade it for a full size rifle later, but we're keeping it to pass down to their kids some day. That Dakota has accounted for a lot of trophies, including a full Namibian bag x2!

My oldest graduated to a full size Ruger M77 Hawkeye in 7mm when he was about 14 and has shot nothing else since (except when hunting anything the 7mm is clearly not appropriate for - he just killed a Cape Buff in Zambia in July with a .375H&H).

My youngest (who is 14 this year) got a Model 70 Featherweight in .308 two years ago and that is now his "go to" rifle.

No flies on the 7mm-08, but the .308 certainly did the job for us for many years and continues to do so.

Kim-
Great choice! The 7mm-08 is like a .243, only more so. Shooter kindly, accurate, with a variety of great bullets available. I love mine, still looking for a reason to take it to Africa.
The choice of rifle is excellent as well, definitely a cut above most youth models. I suspect that its being called a compact will help him to regard it not as a "kid's gun," but rather the serious rifle it is.