In 1956, Winchester introduced a rifle called the “African” for their newly designed cartridge, the 458 Winchester Magnum. Their aim was to increase the number of sport hunters from the US who went after big games on the safari in Africa. The 458 Winchester Magnum is a belted, straight-taper cased, rifle cartridge. It was first chambered in the Winchester Model 70 African rifle. It was designed to compete against the .450 Nitro Express and the .470 Nitro Express cartridges used in the big-bore British double rifles.
The 458 Winchester Magnum was designed for hunting dangerous game animals by emulating the performance of powerful English double rifle cartridges in a bolt-action rifle. Current performance standards for the cartridge allow it to launch a 500 gr (32 g) bullet at a velocity of about 2,150 ft/s (660 m/s) through a 24 in (610 mm) barrel. The 500 gr (32 g) bullet is seen as the standard weight for a 45 caliber (11.43 mm) rifle bullet. This bullet has a sectional density of .341, which provides the bullet with a high penetrative value at a given velocity. The .458 Winchester Magnum loaded with the 500 gr (32 g) solid bullet provides adequate penetration for a dangerous game.
This rifle cartridge was a success, as it soon became the standard African dangerous game cartridge. This made game hunters, game wardens, wildlife managers, and professional hunters soon switch to it as their duty rifle. By 1970, issues with the cartridge began to surface. Due to the clumping of the powder charge and the erratic burn characteristics associated with such loads, the performance of the cartridge came into question. However, the .458 Winchester Magnum remained the standard of measure for dangerous game cartridges. It still remained a very sensible choice for hunting down buffaloes and elephants, though proper consideration needs to be taken on the loads and bullets.