Growing up, I had a school mate chum who used his dad's model 12, 16 bore for upland birds, but when it came to shooting ducks or European Hares in the winter time, he used his own bold action Mossberg with 3" #4's on ducks and 2" on the bunnies. It also had a crank down choke which was on modified for ducks and cranked right down tight for the hares(& fox). It worked for him. So did the 16 on grouse and pheasant with #6's, seems to me - 1 ounce high brass.