If he is going out to hunt deer and has practiced enough and is serious then we are talking about a "Hunter" , not just an arrowhead for our kids.

With only 40 pounds he needs a broadhead with more rake on it for penetration. Definatly a cut on impact fixed blade broadhead. I like for him..

Steelforce Sabertooth, Montec G5, Muzzy Phantom, etc
there are dozens to pick from. Good luck to him.