.450 Rigby
| .450 Rigby Rimless | ||||||||
|---|---|---|---|---|---|---|---|---|
| Type | Rifle | |||||||
| Place of origin |  UK | |||||||
| Production history | ||||||||
| Designer | Paul Roberts | |||||||
| Designed | 1994 | |||||||
| Manufacturer | John Rigby & Co. | |||||||
| Produced | 1995 | |||||||
| Specifications | ||||||||
| Parent case | .416 Rigby Rimless | |||||||
| Case type | Rimless bottlenecked | |||||||
| Bullet diameter | .458 in (11.6 mm) | |||||||
| Neck diameter | .487 in (12.4 mm) | |||||||
| Shoulder diameter | .571 in (14.5 mm) | |||||||
| Base diameter | .589 in (15.0 mm) | |||||||
| Rim diameter | .590 in (15.0 mm) | |||||||
| Rim thickness | .065 in (1.7 mm) | |||||||
| Case length | 2.894 in (73.5 mm) | |||||||
| Overall length | 3.750 in (95.3 mm) | |||||||
| Case capacity | 133.01 gr H2O (8.619 cm3) | |||||||
| Primer type | Large rifle (magnum) | |||||||
| Maximum pressure | 58,000 psi (400 MPa) | |||||||
| Ballistic performance | ||||||||
| ||||||||
The .450 Rigby also known as the .450 Rigby Rimless is a .45 caliber (11.6 mm) rimless, bottlenecked cartridge intended for the hunting of heavy dangerous game. The cartridge is based on the .416 Rigby necked up to accept a .458-inch (11.6 mm) bullet.[1]
History
In 1993 Paul Roberts (the then owner of John Rigby & Company) was on an elephant hunt in the Zambezi Valley. Both he and his professional hunter, Joseph Wright, were armed with .416 Rigby rifles. An elephant was located and then shot in the lungs, but due to a misjudgment in distance several more rounds were required to finally bring down the elephant.[2]
After this experience, Paul Roberts felt that a cartridge with a greater bullet weight of a larger caliber would have been more effective in that situation. After Paul Roberts returned to the United Kingdom he necked by the .416 Rigby case to .458 caliber. The new cartridge fired the 480-grain (31 g) of the .450 Nitro Express cartridge at a velocity of 2,378-foot-per-second (725 m/s) from a 25.5-inch (650 mm) barrel. The new cartridge was given named the .450 Rigby Rimless in 1994.[2]
Performance
Unlike many of the modern .458 caliber dangerous game cartridges like the .458 Winchester, .458 Lott or the .460 Weatherby Magnum, the .450 Rigby was designed to operate at more moderate pressures. Maximum pressure limits enforced by CIP is given at 4,000-bar (58,000 psi). At these pressures, the cartridge easily reaches the intended 2,300–2,400-foot-per-second (700–730 m/s) with the 500-grain (32 g) bullet.[2] The lower pressures provide greater operational reliability in tropical environments where the cartridge is intended for use. Heat can cause higher than normal pressures which can lead to difficulty in extracting the spent case. In a dangerous game hunting situation such failures can result in injury or possibly a fatality.
Handloaders can take advantage of the wide range of .458 caliber (11.6 mm) bullets available. Acceptable bullets weight range from 300-grain (19 g) to 600-grain (39 g). The 500-grain (32 g) bullet can easily reach 2,500-foot-per-second (760 m/s) and staying within the pressure limitation imposed on the cartridge.
References
- ^ Barnes, Frank C. (2006) [1965]. Skinner, Stan (ed.). Cartridges of the World (11th Edition ed.). Gun Digest Books. p. 399. ISBN 0-89689-297-2.
{{cite book}}:|edition=has extra text (help); More than one of|pages=and|page=specified (help) - ^ a b c Haley, Charlie. "The .450 Rigby Magnum Rimless:-A Look At the Cartridge and a Rifle" (PDF). African Hunter. 11 (1). Harare, Zimbabwe: Mag-Set Publications: 45-48. Retrieved 28 September 2010.