OK Lets go devils Advocate here.
What sort of desperation drives people to "Poach" an Elephant anyway.
They are not easy to kill. Shooting at an Elephant is about the 9th grade of stupid really. (Unless you are packing a small cannon, and even then they are still no pushover)
They are massive, they have skin that is inches thick.
A Gun that would blow a human to pieces would just **** an Elephant off and make it even madder.
Hell, you could probabally empty a whole clip from a AK and even if the wounds did eventually kill it, it would still have a minute or so to stomp you into the ground and grind you into slurry.
19th century "Big Game Hunters" Elephant guns were massive. 4 bore, allegedly even 2 bore (2 bore = a half pound solid shot)
They might have looked like side by side shotties, but they weren't.
The second barrel was so that you had a chance if you missed with the first one, though in practice trying to take a second shot after being nearly knocked over by the recoil from first one would be something of a forlorn hope.
The really sad thing is that typically, those at the sharp end (As it were) will only get a couple of hundred dollars a tusk. perhaps not even that.
And that is a hell of a thing to kill an Elephant for, and even more so to risk your life over!