Patterns not much larger than a paper plate. Look at the Federal loads with the flight control wad. The reduced recoil loads offer amazingly small patterns. You should also see increased penetration, as the lower impact velocities reduce pellet deformation.
Also take a look at the Tri-ball loads from Dixie Slugs. IIRC, 3 62 caliber balls. Now that's BUCKSHOT! I haven't tried 'em myself, but they seem to have a strong following.