There was a 12 bore Lancaster Colindian for sale some 10 years ago that did not have a rear sight (rib never cut for read sight). I was told that this paradox rifle was set up for point shooting at close (50 yds or less) game.
The low & high sights on my Tolley 500 BPE will lay flat which gives a view like shooting a shotgun. Out to 50 yds, it does fine.