Just thinking back to an old post by a member who got to shoot some experimental 12G loads from remington that were running about 2000FPS IIRC. What do you suppose a modern handloader can do with a modern gun? Recoil isn't an issue as long as the gun isn't taking a thrashing and within the realm of safety. There is very little for 12G data that I can dig up and nothing that goes beyond factory ballistics. Definitely not getting into reloading 12G if I am not going to see a marked increase in performance.