I have an M1 and I wouldn't trade it for anything else. I thought the same thing as you about the SBE and not needing the 3 1/2 inch chamber. You really don't. I've had vey good luck with my M1 and it has jammed on me but only once and I was using low brass shells and it hadn't been cleaned after going on 15 hunting trips and having it basically caked with mud, water, ice, weeds, even a little sand. I cleaned it put it back together and haven't cleaned it again so far. That was about 1 month ago. They're light, fast shooting, very little recoil, great swinging, they pattern excellent, and they very durable. I love it. Alot of guys will say yeah you need a 3 1/2 inch to kill geese. Yeah if your shooting at them when they're 70-80 yards in the air which I personally don't. If you have any doubt about killing a bird don't shoot plain and simple. So far this year with my M1 I've killed 10 geese, and 53 ducks. I can't say enough great things about the performance that my M1 offers and the manufacturer that makes it. Any of your waterfowling needs will be answered with this gun. But this is just my experience with it some other guys or gals may have a different story to tell about them but I can't think of a better autoloading gun for waterfowl.

Wait, wait, ready PLUG EM!!!!!