back in my younger days I worked in a feed store and I was the official "rat killer" of the crew. The owner had a .22 magnum H&R revolver and I have shots tons of rats with CCI .22 magnum rat shot. I could hit them running along ceiling beams from a pretty good distance. Personally, I don't shoot snakes any more, but if I were to start back I would use CCI rat shot and not worry about it. Well, actually I would use a regular .22 bullet, but if your friend can't hit well enough with a pistol then the CCI will do the trick.
My grnadmother used to pay me to shoot snakes, bullfrogs, and blackbirds and I used a pellet gun. No telling how many she has killed with a hoe.
