I went through the same thing when looking at longer-range computer ballistics with the .300 and .338 Winchester Magnums years ago, both of which I've used extensively over the decades. It seemed the .300 would indeed be superior with bullets around 200 grains, but when actually shooting both rounds with 200-grain bullets there just wasn't any noticeable difference, either in wind-drift or trajectory, out to 500 yards. And that's far as I've ever shot at big game. (Might shoot longer in the future, but maybe not.) This was somewhat puzzling, but eventually I concluded the 200-grain Ballistic Tip's BC was higher than listed by Nosler. Or at least it is in typical hunting conditions in my part of Montana.
I thought for years that there is no way a 200 grain .338 Ballistic Tip/Accubond has a .414 BC if a 165 .308 version(basically same SD) is at .475. I even made a thread asking about it at one point, but no one had any real world results back then. Since then, Bryan Litz has tested the .338 200 Accubond at .461. He also shows the .308 165 at .446, .308 180 at .482, and the 200 grain .308 Accubond at .524.
