My 20 Ultra Slug has a weight in the stock also, bought it new last month at Gander Mountain. Dislike the weight, but it helps manage recoil.
Gun seems to like the Remington Copper solids (new) and groups less the 2" at 100 yrds. Tried the Buckhammers, Federals, Winchesters with poor performance.
Has anyone tried the Hornady shotgun sabots ?