Just about any bullet made is designed for the 270 win. if your son is younger I would go with the lighter bullets to reduce recoil. 4831 is classic but R26 is my new go to powder for bullets 130 grains +.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli