I do my pheasant hunting without a dog and have been limiting my shots to about 30-35 yards or so as I have noticed that shots beyond that range results in more cripples and runners. I've been using an old 20 gauge Bernardelli Gamecock sxs with 25" IC and mod barrels that I bought back in 1970. I've been wondering how much better performance I would get out of a 12 gauge with it's heavier shot loads and slightly higher velocities. About 50% of my shots are at fairly close range so I am reluctant to go to something with modified and full chokes. In researching 20 gauge ballistic tables, most 1 ounce loads get about 1220 FPS. 1 1/8 ounce short mags and 3" mags get 1175. How effective are these magnum shells with thier heavier shot loads at reduced velocities? I normally use #6 shot.