RE: Smooth Barrel, Rifled Slug, 1st Resuts
I shoot a Reminton 870 smoothbore using Federal Maxim slugs on a regular basisis at work. With just the bead sight you should be able to get consistant hits out to about 50yds or so. If you go to a rifle sight or ghost ring sight you will have no problem getting out to 100 with practice.
And yes the wadding comes out with quite a bit of force. Our targets are all along sheets of plywood and they easily punch through the plywood out to about 40 yards