"This barrel will fit non-magnum caliber Savage model 10, 11, 12, 16, 110, 111, 112, 114, and 116 rifles. Barrels will fit magnum caliber Savage models listed above only if the action was originally chambered for belted magnums with a nominal .532" case head diameter such as the 300 Winchester Magnum. Barrel will not fit Savage large thread actions originally factory chambered for the Remington Ultra Magnum, Remington Short Action Ultra Magnum, Winchester Short Magnum, Winchester Super Short Magnum or Lazzeroni cartridges with a .550" or larger case head diameter."
Found this on Midway's sight were they were selling Savage Barrels. It seems Savage used a larger diameter barrel for the WSMs. I'm not sure if someone sell a WSM aftermarker barrel that would be suitable with the regular action.
I have a long action 7mm Rem Mag I plan to convert to 22-250.