Modern Reloading SE lists 124gr j-bullet using Win 231 4.2 - 4.5 (Velocity & psi are the same as Winchester data below).
Lyman 48th lists Win 231 3.9 - 4.4 (960 fps 27,000 c.u.p. - 1043 fps 32,000 c.u.p. This is for a HP bullet but I don't think that matters).
Winchester manual lists Win 231 4.2 - 4.5 (1005 fps 28,800 psi - 1060 fps 32,700 psi).
I am assuming this is the type of info you wanted. Hope it helps.