270 Winchester is a suitable cartridge for hunting deer-sized game at open ranges making it suitable for plains game and mountain hunting. Standard ballistics tests show that the .270 is highly appropriate for hunting screeching boars and pigs. 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 3060 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 1500 ft-lb. of energy up to 400 yards, which is considered the minimum suitable for elk.
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 to become arguably the flattest shooting cartridge of its day, only competing with the .300 Holland & Holland Magnum, also introduced in the same year.
As the .280 Remington, and the .30-06 Springfield, the .270 Winchester 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.
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.