Deanf. I don't know about the .300 Savage round being discontinued, but several months back I posted somewhere, that Olin Corp. (Owners of the Winchester name) dropped quite a few rounds from their inventory. The 7x57 Mauser, .358 Win. and .458 Win. Mag. among them. Yes! Right! Even the mighty .458 has bitten the Olin dust. They have also discontinued about 7 or 8 of their ball powder line, including the relatively new WMR. I can remember these, because I shoot two of the above mentioned rounds, and Use the .458 brass to make up a wildcat round I play with. (.375x338 Mag. It's easier to form from .458 brass.)
I sent Winchester an E-mail complaining about this matter, and they said that this ammo would be produced on a "seasonal" basis and your dealer could order it from two of their distributors. I may still have the addresses in my files, but am not sure. E-mail me and I'll try to find them, if you want them.