The Pecatonica barrel is straight 12 gauge; the minimal flare is all on the outside. I guess if one wished to, he could get the muzzle re-worked so the bore matches the outside, but from what I have read, it doesn't change the pattern characteristics at all; just make them a bit easier to load in the dark. (as if I would.) Fun to shot, even if the proverbial barn door is safe from beyond 20 yd. or so. That said, I can usually hit about 3 out of 10 clays at 20 yd using a square load of 1oz 7 1/2 shot. It would be a great street sweeper with a handful of buckshot.