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378 Weatherby Ammo

The .378 Weatherby Magnum was designed by Roy Weatherby in 1953.[3] It was an original belted magnum design with no parent case, inspired by the .416 Rigby and headspacing of the belted .375 H&H Magnum.[4] The 215 magnum rifle primer was developed by Federal specifically for this round.[4] The cartridge can hold upwards of 7.13 g (120 gr) of powder. The 378 Weatherby Magnum cartridge also has the double radius shoulder design found on the first and smaller proprietary line of Weatherby magnum cartridges.