While not a shotgun, the .22 RF shotshells, called here "sparrow shot".

I used these in my Dad's Slazenger Lithgow single shot rifle a lot as a kid. Pigeons in the shed, sparrows, starlings, assorted birds. One has to be close. Rats and similar in the sheds. The occasional brwn snake in the shed .22 RF shell shot size is too small for effective use on anything sizable.

How well does a .357 or 44 shotshell work? What sort of shot size is used?