The .460 Weatherby Magnum is a belted, bottlenecked rifle cartridge, developed by Roy Weatherby in 1957. The cartridge is based on the .378 Weatherby Magnum necked up to accept the .458-inch (11.6 mm) bullet. The original .378 Weatherby Magnum parent case was inspired by the .416 Rigby. The .460 Weatherby Magnum was designed as an African dangerous game rifle cartridge for the hunting of heavy, thick skinned dangerous game.

The .378 Weatherby Magnum was designed by Roy Weatherby in 1953. 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. The 215 magnum rifle primer was developed by Federal specifically for this round. The cartridge can hold upwards of 7.13 g 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.