257 WBY MAG 100 GR Barnes TTSX Ammo

.257 Weatherby Magnum 100 Grain Barnes TTSX~ The .257 Weatherby Magnum is a .257 Caliber (6.35 mm) belted bottlenecked cartridge. It is one of the original standard length magnums developed by shortening the .375 H&H Magnum case to approx. 2.5 in (64 mm). Of the cartridges developed by Roy Weatherby in 1944, the .257 Weatherby Magnum was known to have been his favorite, and the cartridge currently ranks third in Weatherby cartridge sales, after the .30-378 Weatherby Magnum and the .300 Weatherby Magnum.