What's the platform? Most of the new .277" bullets that require the faster twist of the 6.8 Western don't have any ballistic advantage over bullets that already existed. There are a few bullets in .284" that really shine, if your goal is to shoot a long way and kill stuff. If that isn't the goal, it doesn't really matter which you pick.
I'd recommend the 280 AI, if in the right rifle where I could seat long bullets close to the lands if I wanted to. But I built a fast-twist 270 Win, with the same stipulation that the magazine allows long-seating long bullets.
