#2 lead shot is my favorite for coyotes, BB is second and #4 buckshot a distant third. My use of a shotgun is in wooded/brushy area where seeing more than 40 yards is rare. This is where I try to use up my old goose loads but I seem to end up with more rounds than I shoot as others give me a box here and there.
The 2s will do a good job on bobcats, as someone else mentioned they are easier to kill than coyotes. I almost prefer shooting cats with a shotgun as the holes are a lot easier to stitch up making for a nicer looking pelt. That gives me a higher price for the pelt which helps pay for a tank of gas.
