.270 Winchester
The .270 Winchester is a rifle cartridge developed by Winchester Repeating Arms Company in 1923 and it was unveiled in 1925 as a chambering for their bolt-action Model 54[3] to become arguably the flattest shooting cartridge of its day, only competing with the .300 Holland & Holland Magnum, also introduced in the same year.[4]
| .270 Winchester | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Type | Rifle / hunting | |||||||||||||||||||||||
| Place of origin | United States | |||||||||||||||||||||||
| Production history | ||||||||||||||||||||||||
| Designer | Winchester | |||||||||||||||||||||||
| Designed | 1923 | |||||||||||||||||||||||
| Manufacturer | Winchester | |||||||||||||||||||||||
| Produced | 1925–present | |||||||||||||||||||||||
| Specifications | ||||||||||||||||||||||||
| Parent case | .30-03 Springfield | |||||||||||||||||||||||
| Case type | Rimless, bottleneck | |||||||||||||||||||||||
| Bullet diameter | .277 in (7.0 mm) | |||||||||||||||||||||||
| Land diameter | .270 in (6.9 mm) | |||||||||||||||||||||||
| Neck diameter | .308 in (7.8 mm) | |||||||||||||||||||||||
| Shoulder diameter | .441 in (11.2 mm) | |||||||||||||||||||||||
| Base diameter | .470 in (11.9 mm) | |||||||||||||||||||||||
| Rim diameter | .473 in (12.0 mm) | |||||||||||||||||||||||
| Case length | 2.540 in (64.5 mm) | |||||||||||||||||||||||
| Overall length | 3.340 in (84.8 mm) | |||||||||||||||||||||||
| Case capacity | 67 gr H2O (4.3 cm3) | |||||||||||||||||||||||
| Rifling twist | 1 in 10 in (250 mm) | |||||||||||||||||||||||
| Primer type | Large rifle | |||||||||||||||||||||||
| Maximum pressure (C.I.P.) | 62,366 psi (430.00 MPa) | |||||||||||||||||||||||
| Maximum pressure (SAAMI) | 65,000 psi (450 MPa) | |||||||||||||||||||||||
| Ballistic performance | ||||||||||||||||||||||||
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| Source(s): Norma, Hodgdon,[1] Hornady[2] | ||||||||||||||||||||||||
As the .280 Remington, and the .30-06 Springfield, the .270 Winchester derived from the .30-03 Springfield parent case and the bore diameter was likely[5] inspired by 7mm Mauser. The .270 Winchester uses a .270 inch (6.86 mm) bore diameter and a .277 inch (7.04 mm) bullet diameter.
History Edit
Introduced in 1925 along with the Winchester Model 54 bolt action rifle under the name "270 WCF" (270 Winchester Centerfire), the .270 Winchester was not an immediate success due to the popularity of the relatively recently introduced .30-06 Springfield, chambered for the M1903 Springfield bolt action rifle, which was commonly "sporterized" for hunting purposes.
However, the .270 Winchester attained great popularity among hunters and sporting rifle enthusiasts in the succeeding decades and especially in the post-World War II period, ranking it among the most popular and widely used big game hunting cartridges worldwide, especially with the widespread popularity of rifle scopes. Shooters started noticing that the .277" caliber cartridge was capable of shooting flatter than the popular 30–06.
The .270 Winchester, conceived solely as a big game hunting cartridge, became very popular, in part, due to the widespread praises of gun writer Jack O'Connor who used the cartridge for 40 years and touted its merits in the pages of Outdoor Life[6][7] as well as other renowned gun writers of the time such as late Col. Townsend Whelen.
The cartridge was initially commercially loaded to drive a 130 grain (8.4 gram) bullet at approximately 960 m/s (3,140 ft/s), later reduced to 930 m/s (3,060 ft/s), demonstrating a high performance at the time of its introduction while being marketed as a suitable cartridge for big game shooting in the 270 to 460 metres (300 to 500 yd) range. Two additional bullet weights were soon introduced: a 100-grain (6.5 gram) hollow-point bullet for varmint shooting, and a 150 grain (9.7 gram) bullet, offering a higher sectional density, which made it suitable for achieving better penetration for large sized deer, such as wapiti, and moose.[3] However, the 130 grain bullet remains the most popular option.
For decades the only other commercial 6.8mm cartridge available for sporting purposes was the .270 Weatherby Magnum, which offered a flatter trajectory based on the larger powder capacity allowed by the belted magnum case, however due to the higher price and offer limit, it never reached the popularity of the .270 Winchester.
Nowadays a new breed of .277" caliber cartridges have been introduced to the market, including the .270 Winchester Short Magnum, which launches a bullet of the same weight 200 fps faster from a short action mechanism; the 27 Nosler, which is even faster but requires a long magnum action, and the recent 6.8 Western, which is basically a modification of the 270 WSM firing a heavier and larger bullet with a higher ballistic coefficient. Nevertheless, none of these new cartridges match the popularity of the old 270 Winchester and offer little advantage for practical hunting purposes.
Other of the main reasons why the .270 Win is still one of the most popular loads is because of its acceptance worldwide. Internationally, ammunition and firearms manufacturers offer this chambering in a wide range of firearm options including bolt-actions, single-shots, lever-actions (such as the Browning BLR), pump-actions (such as the Remington 7600), autoloaders (such as the Remington 7400), and even a few double rifles.[8]
Sporting use Edit
The .270 Winchester is a suitable cartridge for hunting deer-sized game at open ranges making it suitable for plains game and mountain hunting. It may be chambered in standard length actions and though the optimum barrel size is considered to be 24 inches, it doesn't lose much muzzle velocity with 22 inch barrels, making it a suitable cartridge for developing a light mountain rifle.
Loaded with a 130-grain bullet with a muzzle velocity of about 3,060 fps. and sighted to touch 3 inches above line of sight at 100 yards (90 meters), the .270 Winchester will not rise more than 3.5 inches, to touch the line of sight at approximately 270 yards, providing a maximum point blank range of about 325 yards for a 7-inch diameter target, matching the vital area of deer sized game, allowing the hunter to shoot within that distance without having to think about compensating the bullet drop. The cartridge loaded with the 130-grain bullet will also retain 1,500 ft-lb. of energy up to 400 yards, which is considered the minimum suitable for elk.
Performance Edit
Cartridges are commonly available from 6.5 to 10.4 grams (100 to 160 gr) sizes with 8.4-and-9.7-gram (130 and 150 gr) loads being by far the most popular. Though handloaders have a wider range of options with the availability of bullets in a number of weights from 90 to 180 grains (5.8 to 11.7 grams), rifles are barrelled with 1:10 inch twist rifling, which may stabilize bullets up to 150 gr in order to provide the required accuracy expected. Common bullet weight recommendations for shooting different game are as follows:
- 5.8–7.1 grams (90–110 gr) bullets: varmint and small deer
- 8.4 grams (130 gr) bullets: deer size game including mule deer, white tail, sheep, mountain goats, antelope
- 9.1–10.4 grams (140–160 gr) bullets: deer, red stag, elk, moose, caribou, and similar larger animals.[1]
However, bullet construction is more important than bullet weight in order to shoot the heavier game.
Recent introductions of low-drag bullets suited to the .270 Winchester such as the Nosler Accubond Long-Range, Hornady ELD-X and Matrix long-range bullets are promoting renewed interest in the cartridge among long-range hunters.[citation needed]
While it is true that a .270 Winchester case can be formed from a .30-06 Springfield case, the case length of a .30-06 is 63.3 millimetres (2.494 in) while the case length of a .270 is 64.5 millimetres (2.540 in), within .5mm of a .30-03 Springfield. However, "The slight difference in length of reformed cases doesn't make any practical difference."[9]
See also Edit
References Edit
- ^ a b . Archived from the original on 2007-11-11. Retrieved 2007-07-11.
- ^ . Archived from the original on 2010-08-21. Retrieved 2010-08-03.
- ^ a b The Complete Reloading Manual for the .270 Winchester, Loadbooks USA, Inc., 2004, pp.13,19
- ^ Spomer, Ron (May 2022). "270 Winchester: Better Hunting Cartridge Than 6.5 Creedmoor and 30-06?". www.ronspomerooutdoors.com.
- ^ ".270 Winchester".
- ^ Barnes Reloading Manual Number 2 (1997)
- ^ Hornady Handbook of Cartridge Reloading, Fourth Edition (1996)
- ^ Speer Reloading Manual Number 12 (1994)
- ^ Speer Reloading Manual Number Ten (1979), p. 182
- C.I.P. TDCC 270 Win.