I have killed whitetails,mule deer,mountain goat,bighorn and elk with the 257wby.However,you do need to pick your shots more carefully on large game like elk.A bullet like the tsx will not come apart even at 257wby velocities.As far as the vanguard is concerned though,I would noy buy any 257 with a 24" barrel as this cartridge really needs a 26" barrel to take advantage of it's case capacity and bore size.