OK, Im in!! After reading all the other posts, I am confused with some of the replies. This is how I see it. If you are stuck on an island with no other humans, the gun is going to serve 2 purposes.
The first purpose is hunting. You will need something that is accurate, and strong enough to take big game (if needed). If there is a herd of deer 50 yards away, and you have a 22lr, you are most likely not eating that night!!
The second purpose is self defense. Im not worried about squirells and rabbits. If I have to draw my gun for self defense, its probably being drawn on something that can kick my ass! Again, a 22lr is useless.
Rememer, in a situation like this, we are not target practicing everyday. We need to conserve ammo as much as possible. That means to me, the only time I am going to pull the trigger is when im hungry (really hungry) or in life threatening danger. Again, we dont know how long we will be on the island. It could be 2 days it could be 2 years!!! CONSERVE AMMO!!!
With all that being said, my choice would be my 4" GP100 with hot .357 magnums and .357 shotshells. Magnums for the big stuff, shotshells for the snakes and possible small game at really close distances.
I dont need an auto jamming on me in a life and death situation. Assuming we are on an island, the chances of the gun getting dirty, muddy, gritty, etc.... are very good. A revolver will do better under these conditions. Even if I run out of ammo, that GP100 can be used as a club!!!
Thats how I see it...
-George