I have been doing some research on 20 gauge. I looked at a Stoeger Coach Gun side by side and found the 20" barrels were choked improved and modified so I looked up loads. I found you can get 9 pellet 00 but the main load seems to be 20 pellet #3 buck. Mag loads are the equivalent to 12 gauge 2 3/4" but with a longer shot string. The 20 gauge would offer some weight savings in ammo and gun in whatever action type you prefer. Possibly friendlier to smaller shooters. I have seen 20 gauge semi autos recommended for smaller shooters. I used to hunt pheasant with a 20 gauge OU and know it works for that. The Stoeger would be a decent hunter once you got used to the short barrels. 1 oz slug loads are available also. I have also looked at the shorter barrel pump with a Polychoke.