Once a gun is properly fitted NO beads are necessary.Eh - where's the fun in that?
I always assumed that a mid-bead was a static alignment aid to check fit - once the gun was properly fit, the midbead was effectively unnecessary.
Most anything smaller than a goose. Used to hunt Rabbits behind beagles in brush and a short barreled model 67 worked very well. Hunted squirrels and pheasants. If necessary I'd hunt dear with slugs. I'm a fairweather hunter so ducks and geese are not my thing.
We had a Quick Skill kit and got pretty good with it. We could throw a disk in the air and hit it from as far as 20-25 feet. One of the reasons we could hit hand thrown clay birds with a 22 about 50% of the time.
