There are alot of much better choices out there for an adult and would not consider a .223 for deer hunting for myself. I would however not have any problem recommending a .223 for a hunter that is young (under 10) and might be recoil sensitive. If recoil is not a consideration then a .243 or larger would be recommended. Yes.....the youth needs to wait for the best possible angle, etc but isn't that an important part of deer hunting no matter what caliber you are shooting? There should be no reason for a bad shot to be taken if the adult is there to instruct on when to shoot.