I don't have a WSSM but as a subsitute for 4831 or 7828 in those cartridges I'd add Reloder 23 & 26 to my list of candidates. With RL-23 vs H4831 in my .264 it's equally temp stable and accurate, and gives a little more velocity. I haven't tried 7828 with my new .264 barrel but I have had really good results with the magical RL-26, and it should be a candidate in the WSSM since the Creedmoor guys like it. Hodgdon's burn rate chart says you can add IMR 4955 to the list. I'd grab the first one that came available but RL-23 would be my first choice.
