.458 Winchester Magnum | ||||||||||||||||||||
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Type | Rifle / Hunting | |||||||||||||||||||
Place of origin | USA | |||||||||||||||||||
Production history | ||||||||||||||||||||
Designer | Winchester | |||||||||||||||||||
Designed | 1956 | |||||||||||||||||||
Produced | 1956–present | |||||||||||||||||||
Specifications | ||||||||||||||||||||
Parent case | .375 H&H Magnum | |||||||||||||||||||
Case type | Belted, straight-tapered | |||||||||||||||||||
Bullet diameter | .458 in (11.63 mm)[1] | |||||||||||||||||||
Neck diameter | .481 in (12.2 mm) | |||||||||||||||||||
Base diameter | .513 in (13.0 mm) | |||||||||||||||||||
Rim diameter | .532 in (13.5 mm) | |||||||||||||||||||
Rim thickness | .220 in (5.6 mm) | |||||||||||||||||||
Case length | 2.500 in (63.5 mm) | |||||||||||||||||||
Overall length | 3.340 in (84.8 mm) | |||||||||||||||||||
Rifling twist | 1-14" | |||||||||||||||||||
Primer type | Large rifle magnum | |||||||||||||||||||
Maximum pressure | 60,000 psi (410 MPa) | |||||||||||||||||||
Maximum CUP | 53,000[2] CUP | |||||||||||||||||||
Ballistic performance | ||||||||||||||||||||
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Test barrel length: 26" Source(s): Accurate Powder[1] |
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.[3] 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.