I once shot a huge warthog bore with a borrowed .243 Sako and 100-gr Nosler Partitions. It was a going-away shot and the bullet entered on the left hip and exited on the point of the right shoulder. I have since shot quite a few smaller antelope such as blesbuck and impala as well as a number of warthogs (as well as a kudu bull, but I won't try to duplicate that stunt anytime soon) with the .243 and either 95/100 gr Partitions or the 90 gr Swift Scirocco. Both bullets give very good penetration, especially the Partition, and they will do fine for what you have in mind.

If I were you I would load the Partitions to about 3 000 ft/sec and not worry about a thing. If your son places the bullets well everything you mentioned will go down in their tracks.