The 260 Remington and 270 Winchester are 2 cartridges that are only 10 calibers off from each other and are often used for the same tasks. So it would only make sense to compare the two to see which one is better.
Here is the short answer:
The 270 Winchester will have more energy and a flatter trajectory than the 260 Remington. However, the 260 Remington has less recoil and a better ballistic coefficient. Overall unless you are hunting big game animals like elk or moose, both cartridges will perform very similarly.
With the short answer out of the way, we can look in-depth at each cartridge, which cartridge is better for which situations, why one cartridge might be better overall, and the best applications for each cartridge.
The 270 Winchester
The 270 Winchester is a 30-06 case that is necked down to a 27-caliber bullet. The 270 was first introduced in 1925 in the Winchester model 54 bolt action. After a not-so-successful launch, the 270 eventually would eventually gain popularity among big game hunters.
The 270 Winchester is most popular among big game hunters and is often considered one of the best calibers for animals like hogs, deer, elk, and caribou. The 270’s claim to fame is that it has high energy and a flat trajectory making it ideal for big game animals and mountain hunting.
The 270 Winchester at 500 yards with a 150-grain bullet, a 270 Winchester has 44-inches of drop and 1200 foot-pounds. Compared to the 30-06, the 270 has only 200 less foot pounds and 10 inches less drop so it is basically just a lighter recoiling, flatter shooting, and slightly less powerful 30-06.
The 260 Remington
The 260 Remington is a cartridge that is common for bench rest shooting and big game hunting. The 260 Remington was released in 1997 and is basically a 308 Winchester case that is necked down to a 26-caliber bullet.
The 260 Remington is a cartridge that is very popular among bench rest shooters and deer hunters. The 260 Remington has a high BC (ballistic coefficient), so it is great at not being affected by wind or gravity. Because of this high BC, the 260 Remington is good for long-range shooting and hunting.
The 260 Remington, with a 140-grain bullet at 500 yards, has just under 1000 foot-pounds and 48 inches of drop. When compared to the 270 the 260 Remington has 4 inches of more drop and 200-300 less foot-pounds.
Which cartridge is better
Since we have looked closely at each caliber we can see which caliber is the best.
If you want a cartridge that is good for long-range shooting, you will want the 260 Remington. The 260 Remington has a better BC, nearly the same drop, and nearly the same wind drift as the 270, all with less recoil. Because of this, it makes the 260 Remington a better long-range cartridge.
If you need a big game cartridge, you will want the 270 Winchester. The 270 Winchester has more energy than the 260 Remington making it better for hunting big game such as elk or even moose.
For your standard deer hunting scenarios (shooting 200 yards across farm fields), then you will want the 260 Remington. The 260 Remington has plenty of energy to take down a deer, will do less damage to meat, and will have less recoil.
Conclusion
If you were to pick one cartridge for the best overall performance, you would want the 270 Winchester. The 270 is a more common cartridge and can be used for more scenarios than the 260 Remington. While there are very specific times you may want the 260 Remington, it is often a better choice to go with the 270.