.357 mag revolver, 6-8inch barrel.... good enough for elmer keith, more than good enough for me

Honestly for what you are looking for, I think a Hi Point would work. They are inexpensive and will get the job done. Plus the lifetime no questions asked warranty, made in the USA, and made pretty solid i may add..

If you are looking for an inexpensive sidearm than I think those are a good option.. Not the best looking gun or the lightest, but will get the job done.

For a "10-15 yard finishing headshot," a .357 magnum or a .45ACP loaded with hardcast lead or FMJ should work fine, and you should be able to find something used in your price range.

I carry a 10mm Glock G20 when walking around in hog areas, because it has 16 rounds of .41 magnum power (almost), but you likely wouldn't find a used one, and a new one is about $600. 10mm is also available in a pretty good CZ-75 clone, the EAA, and you might latch onto one of them in the $450 range.

The 357 is a good round,but you're playing with some big stuff in the mix.You can find a used Ruger Blackhawk reasonable.Yea it's SA,but these will take a diet of 180gr slugs to dump someone's butt.Stay Ruger if you want a DA because Smith and Colt don't handle lots of full power ammo.I would find an old 45LC Blackhawk,odd caliber but it can be found real reasonable to cheap.It isn't a 10 or more,but a slow charge of powder under a heavy bullet in one of them will definately define the term lifespan.The rounds aren't cheap if you can't reload them,but big pigs on a mission need to drop fast.

Where I am,a 400 pounder is big,but still fast and ornery like Grandpa.I like a big hit over thowing a fast volley of weaker rounds,you can pull 2 heavies off in a SA before you do 3 in a DA.

i'd go for the 45acp or the 44mag
depending on what critters you may come up against