A six inch group at 75 yards from a smooth bore (with a rifled choke tube), and open sights seems pretty good for me. Im not a well practiced shooter, so Im pretty happy with it.
If I were shooting sabots, Id EXPECT better results. New technologies, greater expectations. Foster style slugs arent cutting edge technology, but still work. (Ive taken many deer with a patched round ball out of my muzzleloader - and it still works.)
Im still thinking of a barrel..or a whole new gun.. Its more on a tinkering thing then a need.
kb