Good Morning Badboy124,
Fusion projectiles seem to have a feeble track record for penetration.
Nobody I know here in Alaska uses them, that I know of.
My vote is with those who suggest tougher projectiles for Africa, and with those who prefer an exit wound, "blood out/ air in".
As per my personal experience, for thin skinned game, I like Hornady RNSP (and "solid" where applicable, IE: Klipspringer, geese, etc, etc), also Nosler Partition and for the Record, Remington Core-Lokt, in that order.
HOWEVER, for larger animals (moose, bear, eland, guldang wilderbeests, etc), only use these "old fashioned bullets" in HEAVY FOR CALIBER weights, the .308 possibly can't shoot them well over about 165 gr (accuracy, magazine length, etc).
A PH friend of mine (John Luyt / Duke Safaris) keeps a .308 for clients to use and he culls with it.
His load for client's to use is the 180 gr A-Frame but, that bullet is reportedly not accurate in all .308 rifles.
Perhaps the 150 or 165 grain TXS and TTSX or whatever they're called, might be the thing for your son's .308?, you can reportedly use lighter weights/higher velocity with these, than with the bullets I recommend, indeed the TXS / TSSX possibly have to go fast or not expand, due to their lead-free, monolithic hard metal composition.
Nowegianwoods has sacked quite a bit of game with them and he recommends them highly.
Others have had good luck with them as well but, I notice they primarily use them in lighter weight for their calibers and thereby drive them at relatively high velocity and as such, they reportedly penetrate very well indeed, due to their "toughness".
Light weight rather soft bullets are not the best tool in your box for taking large/tough animals like some of the African PG species.
Regards,
Velo Dog.