Check with Jim Briggs at Northland Shooter Supply.
He would be the best bet for a new unfired one at a decent price.
Also a paid membership at savage shooters.com will get you into a Savage only classified section that is well worth the membership $$.
Savage stuff also come up frequently on 6mmbr and the campfire. But you'll have to beat me to it.
I love the heavy Savage barrels. I have stainless heavy fluted in 300win, 220 swift, and a 22-250 LRPV barrel.
And just to bust your chops a bit. A 300wsm would be a short action, so it would come from a model 12.