|Type||Rifle / hunting|
|Place of origin||United States|
|Bullet diameter||.277 in (7.0 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||65,000 psi (450 MPa)|
|Source(s): Norma, Hodgdon, Hornady|
The .270 Winchester is a rifle cartridge developed by Winchester Repeating Arms Company in 1923 and unveiled in 1925 as a chambering for their bolt-action Model 54. The cartridge is the same length as the .280 Remington, both of which are longer than the .30-06 Springfield. The .270, .280, and .30-06 were all derived from the .30-03 parent case that came from the German 8x57 Mauser case which itself was based on the earlier 7x57 Mauser case. The .270 Winchester uses a .270 inch (6.86 mm) bore diameter and a .277 inch (7.04 mm) bullet diameter.
The .270 Winchester became a very popular cartridge due to the widespread praises of gunwriters like Townsend Whelen and Jack O'Connor who used the cartridge for 40 years and touted its merits in the pages of Outdoor Life. It drives an 8.4-gram (130 gr) bullet at approximately 960 m/s (3,140 ft/s), later reduced to 930 m/s (3,060 ft/s). The cartridge demonstrated high performance at the time of its introduction and was marketed as being suitable for big game shooting in the 270 to 460 metres (300 to 500 yd) range, when that was considered long-range hunting. With modern bullets and optics, it is easily a 1,000 yard cartridge. Two additional bullet weights were soon introduced: a 6.5 grams (100 gr) hollow-point bullet for vermin shooting, and a 9.7 grams (150 gr) bullet for deer, elk, and moose in big-game hunting. Renowned gunsmith Harold Fredd considers the 270 to be one of the most versatile cartridges for North American hunting and has recently started promoting it for small to medium-sized plains games.
While not an immediate success, over the succeeding decades and especially in the post-World War II period, the .270 Winchester attained great popularity among gun owners, metallic silhouette rifle shooters and hunters, ranking it among the most popular and widely used cartridges worldwide. Internationally, firearms manufacturers now offer this chambering in all firearm varieties: 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.
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. Handloaders have a larger range of options with the availability of bullets in a number of weights from 5.8 to 11.7 grams (90 to 180 gr). Common bullet weight recommendations for shooting different game are as follows:
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.
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."