OK. First thing I gotta ask...
You're way the heck out in the woods or desert or whatever. You see a snake. Under what possible circumstances is shooting it a good idea?
Let's see. If you're somewhat aware of surroundings and avoid it, there's no reason to blow it away. If it's around a ranch or farm or suburbia yeah, I can see killing it...but a shovel is a better tool for the job 9 times outta 10.
But if it's out in the middle of nowhere? Why kill it? It's part of the ecosystem.
If you've been wandering around unaware, look down and Mr. No-hips is right next to your foot, for God's sake JUMP! Way better odds that way than trying to pull a gun out and shoot the sucker without also putting a bunch of pellets into your friggin' leg.
So. Please, somebody explain to me, why in God's name anybody would shoot a snake (poisonous or otherwise) out in the back country unless they were pretty dang hungry?
Mind you, I think carrying some snake shot along IS a good idea but not to have loaded in the gun - it's there as food-getters against any sort of small game if you're in a bind calorie-wise - scaly, furry or feathery.
Now. As to calibers.
The 357Mag and 10mm are more or less a wash in terms of bullet energy. The 357Sig lags, esp. if the bullet weight goes up past 125gr. And in terms of projectile shape, no autoloader can keep up with the sort of stuff you can run though a revolver. If the goal is to try and stop a charging black bear, there's no autoloader rounds available in 10mm that can touch a 357Mag loaded with 180gr flat-nosed hardcasts running balls-out as loaded by Buffalo Bore, Doubletap or Grizzly Ammo.
This goes triple for the 44Mag...but that means a bigger gun and less total ammo capacity. If I was on a long backpacking trip anywhere in the lower 48, I think I'd rather have a 357Mag due in part to the amount of extra ammo I can carry over the 44Mag, 45LC or the like.
Oh. One more thing. When we're talking bears and you're way out in the woods, a warning shot can be a good idea. I do not EVER ever ever recommend warning shots against humans but they can make sense against animals, esp. away from urban areas. Against a human, a warning shot is just the signal that it's now time for both parties to begin trying to kill each other with all possible haste. Against a critter, different story.