.270 Weatherby Magnum
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| .270 Weatherby Magnum | ||
|---|---|---|
 .270 Weatherby 2nd from left |
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| Type | Rifle / Hunting | |
| Place of origin | USA | |
| Production history | ||
| Designer | Roy Weatherby | |
| Designed | 1943 | |
| Manufacturer | Weatherby | |
| Specifications | ||
| Parent case | .300 H&H Magnum | |
| Case type | Belted, bottleneck | |
| Bullet diameter | .277 in (7.0 mm) | |
| Neck diameter | .303 in (7.7 mm) | |
| Shoulder diameter | .492 in (12.5 mm) | |
| Base diameter | .512 in (13.0 mm) | |
| Rim diameter | .531 in (13.5 mm) | |
| Rim thickness | .220 in (5.6 mm) | |
| Case length | 2.55 in (65 mm) | |
| Overall length | 3.25 in (83 mm) | |
| Rifling twist | 1-10" | |
| Primer type | Large rifle magnum | |
| Ballistic performance | ||
| Bullet weight/type | Velocity | Energy |
| 110 gr (7.1 g) HP | 3,528 ft/s (1,075 m/s) | 3,041 ft·lbf (4,123 J) |
| 130 gr (8.4 g) X | 3,338 ft/s (1,017 m/s) | 3,217 ft·lbf (4,362 J) |
| 140 gr (9.1 g) BT | 3,242 ft/s (988 m/s) | 3,268 ft·lbf (4,431 J) |
| 150 gr (9.7 g) SBT | 3,161 ft/s (963 m/s) | 3,329 ft·lbf (4,514 J) |
| Test barrel length: 26" Source: Accurate Powder [1] |
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The .270 Weatherby Magnum was the first belted magnum based on the .300 H&H Magnum to be developed by Roy Weatherby. It has the characteristic double-radius shoulders and is necked down to accommodate the .277in bullets. Being a proprietary cartridge, the .270 Weatherby has no official SAAMI maximum pressure limit. Weatherby factory ammunition is loaded to 71,000 PSI.[1] The first Weatherby cartridge to be used in Africa was the .270 Weatherby on a jackal on June 8, 1948. [2]
[edit] Performance
Given its higher pressure and larger case which holds more powder than the .270 Winchester, the .270 Weatherby has about 200 ft/s faster performance with any particular bullet weight. This performance comes at the cost of more recoil and barrel heat. In addition, a long barrel is necessary to take advantage of extra powder to gain maximum velocity. The cartridge is excellent at long-range hunting, but is not well suited to high-volume shooting such as varmint hunting.[3]
For those handloading their own cartridges, this is an easy round to load. It does best with full-power loads and is not well-suited for reduced loads. [3][4] Ed Weatherby, son of Roy Weatherby says that the .270 Weatherby is his favorite caliber. As he puts it, there just isn't a better long-range deer caliber. He goes on to mention that it is also quite effective for elk, and antelope.[2]
[edit] See also
[edit] References
- ^ a b .270 Weatherby data from Accurate Powder
- ^ a b Nosler, Inc. (2002). [www.nosler.com Nosler Reloading Guide], 5th Edition, Bend, OR, USA: Nosler, Inc., 219-224.
- ^ a b Barnes, Frank C. [1965] (2006). in Skinner, Stan: Cartridges of the World, 11th Edition, Iola, WI, USA: Gun Digest Books, 43. ISBN 0-89689-297-2.
- ^ Ackley, P.O. [1962] (1927). Handbook for Shooters & Reloaders, 12th Printing, vol I, Salt Lake City, Utah: Plaza Publishing, 384,385. ISBN 978-9992948811.
