.375 Weatherby Magnum
Rifle cartridge
From Wikipedia, the free encyclopedia
The .375 Weatherby Magnum (9.5Ã73mmB) is a medium-bore rifle cartridge. The cartridge is blown out, improved and provided with the Weatherby double radius shoulder â given the Weatherby treatment â version of the .375 H&H Magnum.[1][2] Unlike other improved versions of the .375 H&H Magnum like the .375 Ackley Improved, the .375 Weatherby Magnum is not a wildcat and existed as a proprietary cartridge until the CIP published specifications for the cartridge.
| .375 Weatherby Magnum | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ||||||||||||||||
| Type | Rifle | |||||||||||||||
| Place of origin | USA | |||||||||||||||
| Production history | ||||||||||||||||
| Designer | Roy Weatherby | |||||||||||||||
| Designed | 1944 | |||||||||||||||
| Manufacturer | Weatherby | |||||||||||||||
| Produced | 1945 | |||||||||||||||
| Variants | .375 H&H Magnum, .375 Ackley Improved | |||||||||||||||
| Specifications | ||||||||||||||||
| Parent case | .375 H&H Magnum | |||||||||||||||
| Case type | Belted, bottleneck | |||||||||||||||
| Bullet diameter | .375 in (9.5 mm) | |||||||||||||||
| Land diameter | .368 in (9.3 mm) | |||||||||||||||
| Neck diameter | .402 in (10.2 mm) | |||||||||||||||
| Shoulder diameter | .492 in (12.5 mm) | |||||||||||||||
| Base diameter | .512 in (13.0 mm) | |||||||||||||||
| Rim diameter | .532 in (13.5 mm) | |||||||||||||||
| Rim thickness | .051 in (1.3 mm) | |||||||||||||||
| Case length | 2.860 in (72.6 mm) | |||||||||||||||
| Overall length | 3.600 in (91.4 mm) | |||||||||||||||
| Rifling twist | 1 in 12 | |||||||||||||||
| Primer type | Large rifle | |||||||||||||||
| Ballistic performance | ||||||||||||||||
| ||||||||||||||||
| Test barrel length: 20 in Sources: Barnes & Amber | ||||||||||||||||
History
The .375 Weatherby Magnum was designed by Roy Weatherby in South Gate, California, in 1944 and put into production in 1945. The original cases were fire formed from .300 H&H Magnum Winchester brass, then from Richard Speer's 300 Weatherby brass[3] before finally settling with Norma as a source for cases. It was also with Norma that Weatherby finally found a source for loaded ammunition.[1] Production of .375 Weatherby ammunition ceased in 1960 but was reintroduced in 2001 due to demand.[2][3]
Comments
The .375 Weatherby was designed as a dangerous game cartridge. The cartridge is able to fire a 300 gr (19 g) bullet at 2,800 ft/s (850 m/s) generating a muzzle energy of 5,224 ftâ lbf (7,083 J)[4][5] with the trajectory of the 30-06 Springfield. This performance level makes it an appropriate all-round African safari cartridge that is usable against plains game species as well. The .375 Weatherby is considered overly powerful for North American game.[2]
Design and specifications
The .375 Weatherby Magnum is an improved version of the .375 H&H Magnum. The parent case is based on the .300 H&H Magnum blown out and necked up to accept a .375 in (9.5 mm). The cartridge features the Weatherby double radius shoulder. The Weatherby Magnum is not considered a proprietary cartridge as the CIP has published specifications for the cartridge.
CIP recommends a 6 groove barrel with groove width of 3.25 mm (0.128 in), a bore à of 9.35 mm (0.368 in) and a groove à of 9.55 mm (0.376 in). The recommended twist rate is one revolution in 305 mm (12.0 in). Case capacity is 105 gr. of water (6.82 cm3). The FreeBore/Leade for this Cartridge is 0.373 thou. as per the Factory Spec's.[citation needed]
Performance
As an improved cartridge the .375 Weatherby Magnum provides a leap in performance over its parent cartridge. The velocity gain over the .375 H&H Magnum works out to be about 240 ft/s (73 m/s) and an increase in maximum point blank range of about 25 yd (23 m) with bullets of equal weight. The .375 Weatherby Magnum fires a 270 gr (17 g) at 2,940 ft/s (900 m/s) generating 5,181 ftâ lbf (7,024 J) and a 300 gr (19 g) at 2,800 ft/s (850 m/s) which generates 5,224 ftâ lbf (7,083 J). The cartridge generates more energy than factory loads for the .375 Remington Ultra Magnum, .416 Rigby or the .458 Winchester Magnum.[citation needed]