To me the one trait that seperates the two types of guns is stocking. It is a rare pigeon gun that isn't stocked to pattern high, I like mine at about 70% above bore line.

My waterfowl guns are stocked/bent to shoot about 55-60% above bore line. I typically just barely float the bird over the muzzle/rib on my waterfowl guns. That keeps me from raising my head to see where the game went.

W. E. Boyd