I had a Winchester single shot that I hunted with when I was a kid. Later, I purchased a .410 side by side double barrel and it's become my favorite hunting and pest control firearm. I've successfully brought home meat from hunting doves, quail, cottontail and swamp rabbits, squirrells, and even took a whitetail deer using a 3 inch slug.
For varmit control I've taken several coyotes near the hen house, skunks, coons, 'possums, armadillos, crows, and a few ferel cats. I had a problem with barn swallows once and used the .410 on them, but they are hard to hit.
I use 3 inch shells exclusively.