You could try to hit it with .22LR bullets, but you need to have a full box of rounds and some time; chances are that the snake won't be cooperating with your plans, and will escape under your house, or into some other most inconvenient spot that you can imagine. Not only many of your shots will miss the snake altogether; those that don't miss will not kill it right away.
If you can afford to fire a shotgun at the location, that's exactly what you may want to do - as long as you are safe from a ricochet. (This is something you have to always be aware of, shooting at such distances and against irregular, poorly absorbing backstops.) If you cannot use a shotgun where you are (such as around your home in a city,) then use a shovel or some other sufficiently long tool. If the snake has to be dealt with when you are in the field, then probably the easiest is to walk around it, since you are wearing snake-proof boots.
A .22LR pistol is a good training tool; you may want to get one just for fun, while you can. Semi-autos are trouble because .22 has not that much energy to cycle the mechanism; .22LR semi-autos are very choosy. Ruger Mark III, for example, won't work with any subsonic ammo. A revolver is a far more reliable tool, especially for a target shooter or a hunter who don't need to reload within a second.
You can take it with you to the field, but I doubt very much that you (or most other people) can hit a varmint with it. Varmints are not stupid, they won't let you come close - and with a pistol a common person can only hope to hit a large target at 25 yards. NRA's basic pistol test requires to hit a 9" circle that is 15 feet away. Imagine a varmint that gives you a 9" target area... it would be called a deer :-) Most varmints are far smaller, and consequently their vitals present a smaller area even at the optimal angle. A ground squirrel, for example, has to be hit within just 1". (There is ammo that is not so choosy, but not in .22LR.) Foxes and coyotes probably could be hit in a 3" circle, unless you want them to suffer for a few days and then die anyway. It is difficult to guarantee such accuracy with a pistol. People do hunt with a pistol, but they use a telescopic sight that makes it much easier not just to aim the weapon, but simply to see the target. In the field most small varmints cannot be easily seen - not only they are small, they are also have protective coloring, and they are hiding. A typical shooting distance against a rodent like a ground squirrel varies from 50 to 200 yards; longer if you are using .223 and the atmosphere is stable. If you want to hunt with a pistol, you need a pretty good one, and you probably need to ask questions on specialized forums.
Specialty No. 9 cubic lead shot is made for ricochet-prone scenarios like storm sewers, talus slopes, etc.
Greetings Greysard:
22LR shot breaks clay pigeons, dispatches small varmints effectively, and briefly immobilizes the larger catagory.
Cheers,
OLA
Haha - you may have seen my comment about trying to take out a copperhead with a Crossman .22 pellet pistol. Even with the long barrel, the one time I did it, it was on the 3rd shot, at close range, and probably more luck than skill.
That NRA test is probably not too far off my estimate of what I think I can do at 10 ft. (allowing for the distance.)
At any rate, a long time ago when I was young, I watched my Dad shoot a snake, oh, maybe 6-7 ft. away, with .22 LR snakeshot, and that did a very nice job (killed the snake — headshot — about as quickly as a snake can be killed.) But, tho’ I am relying on an old memory, the density of the pattern seemed tighter than what it’d be if the barrel of the pistol was rifled. All I remember about the pistol itself was that it was old and had what seemed like a longish barrel. Who knows - my grandfather was a precision machinist & I suppose modifications could have been made.
If it was obtainable / legal, a smoothbore .22 with shot would seem to be good for moderate size snakes, starlings, and rodents. But the consensus seems to be that it’d be hard to get / has that extra tax on it if it was available.
Anyway - lots of good info. in your post - thanks.