I heard/read where you need some sort of bullet with a steel shank in it to penetrate the skull ... I don’t think body shots would stop them very easily ....
Elephant poachers hunt elephants with AK47s.
They just drive up next to an elephant with nice tusks and a bunch of guys with full auto AK47s put about 30 rounds each into it. Elephants are made of flesh just like humans. Poke enough holes into a body and the internal organs will leak blood(among other things) out and then various body systems start to shut down... eventually if enough blood loss, the brain shuts down as well. The more holes, the quicker the process.
If you are trying to make a humane kill...well, that’s a whole nuther story.
And then there is this funny thing we westerners refer to as “sportsmanship”. For some reason, sportsmanship encourages us to use guns with very limited ammo capacity and antiquated loading mechanisms. The use of modern technology such as motorized vehicles is frowned upon.