I probably should have mentioned pepper spray. I have carried it for a long time. Never needed it though.
If you are in a situation where a mountain lion is attacking your spouse/kid/dog...do you really want to be trying to shoot it? Well, maybe if you don't like your dog, but:
I thought I would have no problem shooting one before this experience. Now that I think about it, I wasn't even thinking about shooting a cat before. I heard they are a minimal threat to humans, and it just never really crossed my mind as a legitimate threat. I previously carried a handgun for self defense from people, and for scaring bears away. Pepper spray was carried for bears also, in case they got closer. Now, after the fact, when I can picture my situation more clearly, there is no way I'd take a chance relying solely on a handgun for defense from a mountain lion, or from a bear. Because, if you see one of these cats and it acted anything like the one we saw, it's already going to be on it's target by the time you see it. I assume I'd have a different opinion if I would have experienced a mountain lion slowly stalking us from afar, as outlined below:
It would slowly creep up on us, about a hundred yards away. I, being the superior mammal, a human being, would keenly hear it snap a twig under one of its feet. I would then immediately draw my gun, knowing something is up, and point it right in the direction of the snap, only to lock eyes with the mountain lion, right over my sights. A little squeeze turns the laser on, which despite the bright daylight, I can still see it blazing a imaginary hole, right between its eyes. I would yell that I am higher on the food chain than you, and that you should just leave us alone, with my wife trembling right behind me, holding the dog. Then it would show it's teeth, and come charging right at me, in total rage. At that point I would empty my magazine in the cat, having it drop dead in it's tracks, hearing only the thump of it falling over, and then the clapping and cheering from my wife behind me. We would then go on to take pictures and hug each other in victory.
Let's get real here. That ain't gunna happen, ever.
I'd have to have time to: realize what was happening and recognize the threat (1-2 seconds), take out the pistol (1 second), and fire 10 rounds at it (another 2 seconds). Only one would need to hit it. And that's if I'm on "red alert;" ready to act. If I am lolly-gagging down to the river in my bathing suit to take a swim, it's gunna take a bit longer to think and act.
I said it was 2 seconds from the time my wife said "what's that?" to the time it ducked under cover. Well, OK, 3 seconds, I exagerrated a little. It still covered 50 yards. Fifty, solid, yards, in three seconds. That's reality, and that's why a knife and pepper spray are in best order.