I've seen .22 snake shells... do nothing but tick off the snake... LOL.
A 20 ga or my .357 ..... if I"m going to shoot it. Typically, I go my way and they go theirs. One woman who rented an extra house we had on a farm, said she shot 1-2 rattlesnakes down by a fishing pond every day. She asked how many I had ever killed down there. I told her, "none, never seen any.... because I don't look for them...." .
I've seen rattlers (just not by that pond) , and funny thing.... I walk around them and they seem to want to go on their way too. I've kicked a couple, does that count ? One sprung on me and I reacted by kicking it.... (good boots on).
Truly, rattlesnakes have never given me an issue. I give them respect and they leave me alone. Now, a water moccasin, I'll shoot that sucker if I see one... they are way too fast and have always seemed to want to go right for us.
We used to catch bull snakes and all types of king snakes all the time as kids. We caught one day, and was playing for a couple of hours with it, and my uncle came up, grabbed it and killed it, which upset us a LOT. Then he explained ... it was a Coral snake. We knew what that meant. Hummmm, we had it swirling around thru our fingers, around our necks, etc. and it never acted hostile. That's when I learned Black/yellow/red .. you're dead & Black/red/ yellow are mellow. Uh, he was friendly ...
Many snakes serve a good purpose, don't kill the non-venomous ones. Slit eyes vs round eyes.