Description
PRODUCT DETAILS
The 270 Winchester Ammo 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 to become arguably the flattest shooting cartridge of its day, only competing with the .300 Holland & Holland Magnum, also introduced in the same year.
Thank you for reading this post, don't forget to subscribe!As the .280 Remington, and the .30-06 Springfield, the .270 Winchester Ammo derived from the .30-03 parent case and the bore diameter was likely 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 OF .270 WINCHESTER AMMO
The .270 Winchester attained great popularity among hunters and sporting rifle enthusiasts along 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 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.
SPECIFICATION ON 270 WINCHESTER
| Parent case | .30-03 |
|---|---|
| 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 on 270 Ammo
|
||||||||||||||||||||||||
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, elk, moose, caribou, and some larger animals.
However, bullet construction shall be more important than bullet weight in order to shoot the heavier game.
