The 30-378 Weatherby Magnum is based on the huge 378 Weatherby Magnum case necked down to .30-caliber. Wildcatted for years, it was introduced by Weatherby in 2005. Its extra-large belted case requires a magnum-sized action, and longer barrels (at least 26 inches) are needed to burn its massive powder charge and reach full velocity--but it is the fastest commercial 30-caliber cartridge. Recoil and muzzle blast are severe, and it is an overbore capacity cartridge, meaning that powder selection is limited and throat erosion will be rapid. Despite these limitations it is both fast and powerful, and has thus found favor with today's growing community of long-range shooters. Weatherby is the primary source for both rifles and factory ammunition.
