The Feds do not allow rifled firearms while hunting waterfowl. It is a no no. Many years ago I had a father bring his son goose hunting with one of the Savage M-24 20 ga with 22 mag upper bbl. Kid didn't have any rifle ammo( I made sure of that) with him. Had to talk the game warden out of writing a ticket to the kid. Luckily we hadn't fired a shot on the first day of the hunt and the Federal warden(his name was D'arcy Davenport if I remember correctly) just told us he couldn't hunt with a combo gun. At the same time you are not allowed to have any kind of rifled slug sabot or even an ol punkin ball while hunting waterfowl either. Now in many places across the country where you don't see many Federal Wardens such as where I live now...you probably wouldn't have to worry about it as long as there was no rifle ammo in possession. BTW at lunch I went home and got one of my 1100 20 ga guns for the kid. He even shot a goose or two on his own. Father was tickled as was I.
Just wanted to say also that those ol German guys didn't even think of having a beer during the day(unless we got done early)...but boy did they like to have a few cold ones afterwards...WOW!..They could really pour it down!
I really had some unique experiences guiding during some of the best goose hunting the US has ever seen.. In 3 small counties on the Eastern Shore of Md we had a population of a million or more Canada geese. I had quite a few times when I had a toll(decoying birds) of more than 500 geese. Largest toll was well over 5000. And that toll almost got me thrown into the river by the Professional football player hunters I had out that day. I wouldn't let them shoot!hehe