Rob, to answer your question concerning typical American factory loads . . . the 1 oz 16ga load has a published velocity of 1165 fps. The 1 1/8 oz loads are mostly 1295 fps. So the latter is not only heavier but also faster, which means a significant difference in recoil, which is also a factor where old guns are concerned (especially on old stock wood). American ammo makers don't list pressure, but that's probably higher too on the heavier load.
Found some Federal 7/8 oz factory 16's the other day, figured "Hot damn, they're finally doing something for those of us looking for light 16ga factory loads!" Then I saw that the box says 1400 fps. Without doing the math, I'm pretty sure the 1 ozers at 1165 fps have less recoil.
