RE: .243 bullet choice
I have had good success with Hornady 87 grain bullets. The last few years I've been using Sierra Game King bullets. They seem to be more accurate.
Both these bullets are very effective when chest and neck shots are to be had. Shoulder shots are not advised as a .243 does not have the energy to successfully penetrate dense massive tissue areas and bone.
Well placed chest shots are deadly. I've never had a deer take a single step after being hit in the chest with 85 or 87 grain bullets.
I don't think there's a better caliber to break a youngster in on a high powered rilfle. There's very little recoil from a .243.