I have used 4831, 4350, Rel 22, Rel26, Ramshot Hunter and Magnum, and a few I probably forgot. Trying to be economical and one size fits all, I would go no farther than than H4831 ssc. Bullet weights from 85 to 180gr.
In loading for your grandson, it is easy to make pleasant, effective loads.
I have found starting loads to be satisfactory.
I would look at 110gr NAB, 120gr SST, or a softer 130gr bullet at moderate loads.
If you want to go even lighter, H4895 has been used in this house for many rounds of reduced loads and has accounted for more than a few deer/antelope. Hodgdon has the reduced load information on their website.
