I am going to disagree somewhat with JJ and Flinch. I haven't killed anywhere the number of bears that JJ has and he didn't say how many lion kills he's been on. This isn't my point. You can kill a lion with damn near anything in my experience. I have never had one give me a lick of trouble when hit.
A friend of mine worked as a damage control contractor for several reservations and killed more than 3000 lions in 50 years. I drew a lot of experience from him and chased a lot of them with him too. I think his bear kill was in the neighborhood of 700.
He prefered to kill them with a rifle. He had a 44 but said that a rifle was much better. My only real point is that there isn't much of a "crumple factor" with any reasonable handgun. As for the 9mm and 40s needing more maintenance that is pure ignorance. The chambering of the gun has little if anything to do with reliability of it. Most of my experience is with Glock handguns, but there are others that are also reliable. I have seen them thrown from helicopters, buried in dirt and about everything else and they still go bang just about every time. Some malfunctions are going to happen- that's why cops are trained extensively to perform malfunction drills.
If I were hunting over hounds, I wouldn't feel the least bit undergunned with my 40 S&W on a lion in a tree. It would work on a bear in a pinch but in my experience, you have to wait a while.
If you want instant results, a high velocity rifle round is the real answer. Some may question why all these mediocre rounds are used for this. The reason is simply weight. A houndsman doesn't want to pack a 7# rifle around on his mule all day when he can get by with a 2# handgun.
For the record, a 180 grain Speer Gold dot out of a 40 S&W does a fantastic job on bighorn sheep, lions and humans. I just may know someone who has personal experience in these matters.
