It has been proven through physics that the aero dynamics of a .284 bullet giving the same powder charge as any other cartridge will travel further and retain more speed than any other caliber out there. Thats what is considered the Middle of the road. Plus the bullet weight ranges makes it a better choice than a .277. Thats why they never made a 270-08. Just a better bullet selection.

But saying that I'm a 270 advocate. I believe they are a close second to aero dynamics to the .284 class and the .308 class. I would love to build a 270 STW or a 270 win mag. That would be a mighty fine 600yd plus antelope rifle. But I could just buy a 7 STW and call it a day. You can have RCBS build you dies and a reamer and make your own.