cdb,
It occurred to me that I wasn't quite correct about the 26 Nosler shooting a lot flatter than the .270 Winchester. These days there are a bunch of much lighter .277-diameter bullets designed for the 6.8 SPC, and they can be driven so fast the 400-yard trajectory is almost as flat as the 26 Nosler's with a 129-grain Nosler ABLR.
A friend in eastern Montana, for instance, handloads the 85-grain Barnes TSX in a 24" barreled .270 Winchester to 3900 fps. Admittedly, the load he uses isn't listed anywhere, but the velocity really flattens the trajectory. The downside is that the 85 TSX drifts more than twice as much in the wind as a 129 ABLR from a 26 Nosler--the downside to lighter bullets at warp speed.
Wind-drift is also the "hidden" flaw in comparing most cartridges to various 6.5's. To reduce wind-drift in larger calibers bullets must be much heavier, increasing recoil. Which is why 6.5's are currently increasing in popularity, whether mild cartridges like the 6.5 Creedmoor or boomers like the 26 Nosler. With the advent of laser rangefinders and modern scopes, flat trajectory isn't nearly as important as it used to be. Essentially, minimal wind-drift at longer ranges has replaced flat trajectory as a virtue for many shooters.
