I started with a .30/30 when I was 12, graduating to a .30/06 when I was about 14. I did not like the recoil at all. I did not enjoy shooting, trips to the range were hell. I was not sure that I wanted to pull the trigger when I finally did get on an animal. Now, years later I am fine with the recoil etc. I will do it differently with my son. He will start with a 6mm or something similar. I will back him up on shots on game as my dad did with me. When he is a capable marksman and hunter and can handle a larger calibre, then he will get one. No pressure, no macho business about the recoil. Feel comfortable with shooting, not scared, put the bullet where it needs to go, don't take low % shots. Get him a .243, 6mm, .257R, whatever. Get a good used rifle that you can sell for similar money that you purchased it for, when he is ready to step up. Then again, he may be a monster and can handle the big recoil right now. Don't push him, let him develop good shooting skills, giev him time. No hurry.