I reckon you can forget your ideas of multiple shots etc. From my experience they come for you at absolute greased lightning speed and you're lucky if you get time for one shot, let alone more. Try to imagine skeet shooting at close range and accelerate the whole experience a few times and you get an inkling of how fast they usually are. Then factor in that a Leopard can and usually will, hide behind a single blade of grass....... snap shooting is the name of the game and it helps (if time allows, and it probably won't!) to get low and shoot on the same plane as the cat to increase your chances. Even a double probably wouldn't allow time for the average shooter to get the rifle back on line for a second shot in time. Maybe someone who's very good indeed with their double might make it, but they'd have to be very good indeed to manage it.

I guess an automatic weapon might work if you could control it but as they're not permitted in any African country I know of, the idea isn't really relevent.

As for shooting Lion with a shotgun of any calibre with any size certridge loading at any range...... I think someone's probably been pulling your leg. (IMO) anyone who tried that game is in need of serious psychiatric help. All I can say to that is whilst I wouldn't doubt your or his word, I'm buggered if I'd consider that idea for even a millisecond.