B-Boy wrote:x3 on the M2. I have killed a lot of ducks of all sizes with my 20-gauge M2. Mine likes PMC 3" 1 oz loads of #3 or #4. Although I wouldn't call this gun punishing, the Comfortec stock is also nice for recoil reduction. It's also a light gun. Mine weighs 6.1 lbs with a 26" barrel and extended chokes. Plenty light enough for a day of upland hunting as well as waterfowl. Although I haven't tried it, you could (theoretically) take a goose with this gun and the right shot shells (Kent Tungsten Matrix, Federal Heavy Weight, etc.). I know Britman has done just that with the same gun.
7/8oz of Kent #2 steel dropped my last goose of the season with the M2 in 20ga, but if I'm not loading my own, I prefer the Estate 1oz 3" loads in #3 for ducks and close-enough geese.
The M2 is fun to shoot fast. I can get 2 or 3 shots off before I've taken my first shot with my Beretta 390 12ga. It's light and thin which makes it easier to carry and faster to the shoulder. For me, it slows down time. That's not to say I don't do serious harm with my 12ga, the 20 is just faster. I found mine used last year for $700 (with some heavy use on it) so they're not totally unobtainable. I cleaned it, put in a new spring, and eventually rattle-canned the barrel. I call it the Prom Queen.... you know, 10 years after the prom.