It's all because the .270 sucks.....
This ain't rocket science...
Great comments as usual Bob. All of the gratuitous swipes at the 270 by the usual gang of 'haters' aside, there is an interesting point raised in the OP regarding bullet design. Your points about faster twists and heavier (for calibre) bullets are well taken, and as you've essentially said it is pretty obvious that the 270 isn't going to excel at something it wasn't designed to do well in the first place. However, let's try to eliminate the issue of heavier bullets for the moment. If we consider only the 140 grain bullets in each of .264, .277 and .284 from the OP, there is still an interesting phenomenon. Obviously, at the same weight, the .264 will have the highest SD, and so it comes as no surpise that, given the 'same' bullet design, it has the highest BC as well. However, the .277 has a slightly higher SD than .284 and yet the BC of the .284 is actually a bit higher. It would be interesting to hear some comments from those 'on the inside' with respect to bullet design on why that might be.
