You don't need a Magnum action for a 257 Weatherby (length wise) as it is about the same length as a 270 WCF. So if you have a REAL magnum action (3.6" oal loaded) I would not waste it on a 257 WM. Better to sell it for big bucks and buy a MOA Vanguard.
Will it do anything a 270 WCF will not? I doubt it in practical hunting. It's a favorite Antelope cartridge where I live, but I manage to kill a couple every year and don't own a 257 WM.
Still a neat cartridge and I am no one to talk as I built a 244 H&H.
