Just a quick check at the Legacy Sports website, and I didn't see a listing for the 300 WSM in a barreled action only in stainless.
http://www.legacysports.com/product/specs/howa_actions.htmYou may have to call Davidson's or a distributor of your choice and see what they have to say. Call LSI direct. Get into a good search engine and start looking at each of the listings. GunsAmerica doesn't show any. Gunbroker has complete firearms only in their list.
Best of luck!