![.458 Winchester Magnum History: The Complete Story]( ".458 Winchester Magnum History: The Complete Story")
Introduced in 1956, the .458 Win. Mag. (right) is a direct descendant of the .450 Nitro Express 3 1⁄4 inch (left) and the .450 Watts. (center).
The .458 Winchester Magnum is a fairly modern cartridge, but its story begins back in 1898. That’s when John Rigby, an Englishman famous for building high-quality double-barrel rifles, loaded the case of the old .450 Black Powder Express with 70.0 grains of a then-new high-nitroglycerine-content smokeless propellant called cordite and renamed it the .450 Nitro Express 3¼ inches. Advertised velocity for three styles of 0.458-inch bullets weighing 480 grains was 2,175 fps, but since they were from 28-inch pressure barrels and mixed with a pinch of exaggeration, actual velocity from the 26-inch barrels of double rifles usually ranged from 2,025 to 2,075 fps. Cordite had a...