The .458 Winchester Magnum is a belted, straight-taper cased, Big Five game rifle cartridge. It was introduced commercially in 1956 by Winchester and 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 big bore British double rifles. The .458 Winchester Magnum remains one of the most popular large game cartridges, and most major ammunition manufacturers offer a selection of .458 ammunition.

This is a list of firearm cartridges which have bullets in the 11 millimetres (0.43 in) to 11.99 millimetres (0.472 in) caliber range.Length refers to the cartridge case length OAL refers to the overall length of the cartridge Bullet refers to the diameter of the bullet