I'd start him shooting your 7mm mag and see how he does. The 7mm mag is a pretty light kicker and I really don't think many people could tell the difference between it and a 30-06 or 308 for that matter. Lots of folks will tell you they can but if you put a blindfold on them and had them shoot each one very few could tell the difference. I wouldn't worry too much about his inexperience shooting, teach him the basics and let him burn lots of powder before the season and he'll do fine. I've seen plenty of so called seasoned hunters who couldn't make a 300 yd shot if their life depended upon it, but will sling lead at a deer showing himself at that distance never to cut a feather. Of course, these same guys will have sighted in their rifles on a milk jug sitting on top of a fencepost 20 yds away and upon hitting it proclaim their rifle is ready for anything up to 500 yds (don't laugh, I've seen this done). The difference is that a beginner can be taught to shoot correctly while many old timers never learned to shoot correctly and refuse to learn. I'll take a properly taught beginner anyday over an old timer that thinks he knows everything.