Depends on how far you feel comfortable shooting--but flat trajectory and less wind-drift are not always found in the same bullet/cartridge.

The .257 Weatherby with 100-grain bullets at 3500+ is the flattest-shooting cartridge I've used, pretty much point-and-shoot to 400 yards--where the wind-drift is just about exactly the same as the 6.5 Creedmoor with high-BC bullets in the 140-grain range. Beyond 400, higher-BC bullets at slower muzzle velocities drift less--such as the Creedmoor with high-BC 140s.