You'll want consistent ammo for accuracy I've heard. I'm too lazy to do that, and that's probably why I'm not super accurate. A decent sized rock (around golf ball sized) should easily kill a squirrel. As long as you hit it hard enough it should die.

Our first sling hunting thread: http://slinging.org/forum/YaBB.pl?num=1060288276/0#0
The Rabbit Story: http://slinging.org/forum/YaBB.pl?num=1095082537/14#14

In Alabama, the sling is legal for all non-migratory game birds except Turkey. It is also legal for varmints and small game animals that are not a raccoon, opossum, fox, coyote, or feral pig.

What does that leave? Mourning Doves, Nutria, Rabbits, and the like.

The sling is legal by non-exclusion. The only prohibited weapons are centerfire ammo guns, rimfire ammo guns larger than .22, shotguns above 10 gauge, shot larger than No. 4, and scoped pistols. Even blow darts are specifically mentioned as legal, as well as the sling shot which has an ambiguous definition in Alabama law. Have at, but tread carefully.

I do not have the accuracy to hunt, so I have not tried. You'd be better off not hunting either, at least for the immediate future.

I would think that a good sized rock would stun an animal wherever you hit it, letting you get closer and club it or something. Would a shot in the head be necessary?

as a long time sling hunter, i can tell you this. number one...use larger ammo. use stones, not clay, the size and shape of jumbo eggs. clay doesn't have the density to insure a clean kill that stones do. number two...against small prey such as rabbits, squirells, doves, quail, etc, the sling is a devastating weapon that almost always kills cleanly, or at the very least, stuns and wounds enough to enable retrieval. imagine that you are shot with a rifle. unless it's a head or heart shot, you might very well survive long enough to escape, right? now imagine you are hit by a basketball sized boulder traveling at 100 miles per hour. you're down, no question. the impact shock of sling stones on small game is very effective and has the added benefit of not ruining the pelt.  so, it comes down to this..against small game the sling either misses completely (what usually happens) and the animal gets away, or you hit it and take it home. of the many animals i've hunted with mine i think only one or two ever got hit and escaped.

there was some Gatorade bottle sling as well. the bottom was cut off, with a leather flap over it. the flap was kept in the way of the stones coming out by the release cords. it would work, and i'd think it would be much cheaper than a nice gourd (even thought they're pebbles, the total will weigh maybe more than what your used to).

The Apache sling article describes hunting animals, including deer, with sling.  It is suggested to bring a knife and a first aid kit, and be within 35 meters distance of your supposed dinner.
If the stone just stun the animal kill it with the knife.  Fast.

BTW I once read an Danish deer hunting instruction/manual from 18??(I read it in a book from the 1870s, but it was obviously older).  It was then done at close range from hiding, with an single shot muzzle loader loaded with buckshot.  It was apparent that the shot often did not kill the dear, and the hunter usually had to step forth and cut the throat, stab the heart, or sometimes hamstring the deer to stop it from running.  If all this failed it was time to bring out the dog to follow the blood trail.
This would not be that different from a sling hunters task.

I suppose I`ll be good enough to hunt with a sling after the world as we know it has ended, and it will be an issue for me.
timann