I have been using a Benelli H&K SBE since the early 1990's. I've been killing geese and ducks all these years both in Michigan as well as Canada. I never found that 31/2 " shells kill any better than 3" for geese. I tried all kinds of steel as well as Hevi shot and bismuth and find that they all kill well for me. The last 5 years I bought a Benellli camo M2 and its my favorite now. I been using it with a Cremator MR range choke in it. I shoot the regular blue box Federal 3" #1 steel 1 1/4 oz. for geese and it kills big Canada honkers out to 40 + yards with no problems. They are very inexpensive compared to other brands. I shoot #3 and #2 for ducks and they work great with the same choke. I take about 70 geese and about 40 ducks (mallards and woodies) a year at my friend's small property with a pond. Just me and my dog. It's only 20 minutes from my house. It's great being retired now. Good luck to you.
Love your choice in guns, those are the same two guns I am taking with me on my one day trip. My camo Binelli M2 with a 26" barrel has been my favorite shotgun for a decade. That is why the SBE HK that I bought used, just sits in the safe since I bought it. I need to get a plug for it, or make one. It holds 3 in the magazine right now.... Gives me a task before I head out tomorrow.
