I don't think loading shot into a percussion revolver is going to work very well. I live in snake heaven but I usually just walk around them. Even if a mocassin or diamondback coils up- just walk around them. In all the years of sitting on the ground turkey hunting I've never had a snake crawl up to me, although I suppose it's possible. They eat a lot of rats and vermin. If I'm running around in the pich black of night I wear snake boots, I don't bother during the day.
BTW- the traditional heavy stick is and remains the world's greatest snake killer. When I was a kid I'd always tease a snake with a stick, sort of stupid if you think about it. The only reason I'd kill a snake these days is if it was a trophy sized (8' plus) diamondback, they are getting pretty rare.