This is January so I'm guessing... you're planning on next season?
What I'd do is develop a heavy boolit load for the .357.
Here's why.
Novice hunters sometimes get excited. They can sometimes be better off with a bigger hole for tracking. More penetration punch through; more is better. So, that said, I'd go for a flat point gas checked heavy cast soft and hot loaded with lots of H110 or 296 or some such.
Being for next year there's time for him to grow into it. Heck, I'd let him cast the boolits and teach him reloading.