I think a valid argument could be made for either one. It's a win-win choice. My personal preferance is for accuracy over velocity/trajectory. The .308 has a reputation for being an accurate cartridge with a wide range of bullets, no matter what the gun. While the .270 can be just as accurate, it might be a little easier to achieve that with a .308. "You can't miss 'em fast enough to kill 'em".