I work and play in country infested with a baker's dozen species of rattlesnakes, and have yet to encounter any situation, including while purposefully hunting rattlers around their den sites, in which a handgun with snake shot would have proved useful, vs. simply stepping away. I used to carry a revolver with snake shot, until, after much experience, I concluded that it was not only pointless, but also diminished the real defensive capability of my sidearm. Somebody, somewhere, sometime, may be able to resolve a "confrontation" with a snake by shooting their way out of the situation, but, after lots of encounters, I can't conceive how. I just watch where I step, avoid stepping where I can't watch, and wear snake-proof leggings when I can't watch carefully enough (such as when distracted, as by quail hunting). I'd forget the snakeshot as an ammo consideration...