From my experience, even at close range a shotgun isn't worth shit. I did a night follow up a few years ago in Tanzania with my friend and fellow PH Colin Kirkham from Botswana. He had a 12 gauge and I had my .500. Thi is the follow up I discuss in the article I mentioned.

The animal charged and we both shot at the same moment when the animal was 5 or 6 yards from us in mid air........ my shot went in beside the nose and exited out his arse. Colin got in two barrels and although the shot broke the cat's jaw on both hinges, not a single pellet penetrated more than the skin.

It was that episode that made me decide to come up with my rehearsal technique......

I don't care what anyone else uses on a follow up but I'll stick with my 500.