Hey buddy, I hope you're doing well. I would frown upon this in all honesty however I'll give you the info you're asking for as well as my thoughts on the topic.
Firstly let me start this by saying that I used to breed reptiles and was fairly well know for my line of many snakes in years past. I've also road hunted and found thousands of snakes in the wild from common snakes like the Diamondback to les common like that Sidewinder to rare like the Western Green Rat and the Arizona Mountain King. I have killed very very few snakes, in fact, I can think of two I killed only because it was going to be done by the land owner anyway and there was a good chance he would have gotten hurt. I also knew a friend that wanted to eat them so I did it in part so they wouldn't go to waste.
If you come across a snake you want to kill to eat I would say your best bed it to either pin it very securely and remove the head or better yet have your screw on tip be more of a small shovel you cut flat and sharpened so you can behead it as a distance. I don't think your nail tipped stick is the best solution.
If you do take a snake, try not to take huge adults, look for snakes that aren't full on adults that are contributing to the local breeding population. I think you may be well suited to post on craigslist and say you'll remove snakes and try to get them from a place where they will more than likely end up dead or roadkill anyway.
Come to think of it, I'm not going to try to talk you out of it, just research the snake you're taking and take something that's fairly common. Also, bread and fry it for the best taste.
*****ATTENTION*****
Remember, the cut of head of a rattle snake can still bite you or another animal for hours after it's cut off. If you cut the head off do not touch it and cover it with a large rock or dig a hole for it so a dog doesn't sniff it and get bitten. Also, be sure to gut it fairly quickly.
