Magnum Bob,
I also hunted ducks with a 3" model 12 Heavy Duck; the 3" lead shot shells before steel shot mandated in 1995 were never a problem ejecting. When using 3" steel was not the same as prior 3" lead shells so used 2 3/4" shells while some manufactures were not always reliable. The Model 12 HD was not always the best pumper for 3" shells, in 1935 all shells were paper so was able to extract. Winchester removed 1/4" more chamber port toward the front of receiver for 3" shells so over the years labeled the model 12 heavy duck 3" the best 2 3/4" shotgun pump shotgun for duck hunting.
Just an FYI, I reloaded old style 2 3/4" Winchester AA for both target and hunting, all brass base never an issue with extracting in a variety of model 12's.
