I agree with everyone that an S&W 686 is a fine gun, and also .357 magnum is a great all around caliber, along with .38 spl as a practice/plinking round.
The 357 magnum will down a deer, but then I've seen big whitetail bucks take one or two 12 gauge slugs in the boiler works, and run for another 100 yards or more. My point is, don't count on the .357 as a
great big game cartridge. I've taken a couple deer with .357, however, shot placement is absolutely crucial.
Also, if protecting the homestead, a 12 gauge shotgun loaded with buckshot is a vastly superior weapon, and requires less concentration on the part of the defender. Plus, a shotgun is much more intimidating than a revolver, because the intruder knows that He's in serious trouble, should the defender use it.
Just My .02