I understand that you donít want to gross out your little hunter and possibly turn him or her off to hunting before they have a chance to enjoy all that it offers. The problem I see here is even if you manage to keep a nice and tidy entrance and exit wound, youíre going to have to field dress your trophy and dump all the blood and guts on the ground anyway. What are you going to do when you skin and butcher your animal? The experience of hunting with kids gives you an opportunity to explain not just hunting techniques, but biology and nature (even the gut pile doesnít go to waste).
I have two girls that love to go out to the woods with me. The oldest wanted books on animal tracks and loves the outdoors, but doesnít like hunting - yet. My youngest gets mad if I donít remove the brains and eyes for her to examine.
The one thing you can be sure of is that a bullet and its wound channel can be hard to predict. Do a search of this site and you will see that even premium hunting bullets can fail and come apart
I would hunt with the bullet your using if it's more accurate and explain to your young hunter why and how it may be more humane for a quick kill.