if your gonna shoot the federals id for sure go with a carlsons .575 nonported, best 20ga heavywieght choke ive tried. i dont have a remington superfull but im sure it would be a winner if you can get one... ive got 3 20s (2 H and Rs and a winchester 1300) with INVECTOR threads and have an Indian creek .555, pure gold .570, and a carlson .575. NO DOUGHT the carlson shoots better in all 3 of them when shooting federals. For less than 30bucks its a great flite control wad choke in any gun. Id bet you wont be dissapointed.