I use the Win Super-X in my old fluid steel doubles, but I only use the regular field load at 1 oz. FWIW, I did an informal comparison a few years ago in an LC Smith FW Ideal 16. Shot doves with the Win Super-X, Fed Field Loads, and Rem promo loads from Wally World. All were 3-1/4Dx1ozx7.5, and the Wins were by far the softest shooting of the bunch. There have been discussions over on the SSM BBS about factory shells for old doubles, and the consensus was that the Win Super-X is a pretty good choice.