definatly the .357 and definaly a 180gr bullet and load it fast. i use a load of 15gr. lil'gun and a 180gr XTP. this is out of a 6"gp-100. its listed as a max load at 34000 cup i think. it gives me 1.1"groups at 25yards
took it out with me this fall because i live in indiana and it handgun or shotgun. the round did more than i could have asked. double lunged (really the only choice dont try anything else) a 160lb (field dressed that is) 8point buck, at 25 yards, i wouldnt go beyond 50 unless the animal is already wounded. the bullet hit a rib dead on going in a vaporised a hole thru it, thru both lungs and out the other side at about .5" diameter.
while the 357 is not an optimum round it will do its job provided you wait for the good shot. if you are going to buy one, get a .44, itll be all you ever need but dont discount the 357