According to the Winchester Reloading Manual, there is no load listed using Win 231 powder. I think it would be much too fast a burner. They list WSF and 571 powders only for the 20ga. According to the manual, 16.5 gr of WSF, with 7/8oz shot, WAA20 wad, and Win209 primer duplicates the ballistics of the factory 2 1/2 dram target load.
Don't shoot the messinger. Check out their website. Mikey