I like stoutly constructed bullets in my Weatherbys. I don't own a 257, but my 270Wby is very close in size/use. I use Nosler E-Tips in both it and my 300Wby. But for a 257, I'm not sure what I'd use. Certainly something tough for closer shots, but with expansion at longer ranges. I'm not a huge fan of the Ballistic Tip in magnum cartridges, though I use them almost exclusively in standard chamber inge like 30-06 and such. They are not optimal for impact velocities above about 3,000fps. For me, discussions about Weatherby bullets always involve the monoliths like the E-Tip, TTSX, and GMX, but also include the Partition, A-Frame, and the various bonded cores like the Accubond, Interbond, and Scirroco. Ultimately, it will depend on your anticipated impact velocities, the game you're after, and how selective you will be with your shots.