Welcome to the BBS:
Hope we can assist.
These guns are all heavier than the usual for they were built to last the man that needed a tool for shooting. But, you may be correct that it could be used for waterfowl. I don't think they specifically intended this to be the case, though.
Hope the following will be helpful.
We are a board of many thousands of shooter/collectors. Seems that most of us have a passion for SxS guns and treasure them. Some here will not be pleased that any good and useful SxS or
special gun is cut down and/or modified for action shooting.
We have seen far too many treasures that would grace any fine collection or shooting arsenal with 20 inch barrels that retain the hacksaw marks.
Seems to me that this is not your intention, though. A 311 is not a gun that most would class as a fine shotgun.
Have fun with it and know that any of the shooting sports are worthwhile in furthering our retention of our 2nd ammendment right.
Best,
John