After reading an article on it, I switched to shooting ducks over decoys with trap loads, 1 1/8oz 7 1/2's.
These were in the days of lead shot on waterfowl. I even tried #9's in 20 bore on teal - murderous with no
body penetration at all with either shot sizes, all heads and necks. The feathers would have a lot of shot in them
but none penetrating the skin.