Another government solution to a problem that don't exist. A 115 grain 270 bullet won't hold its velocity well, and it'll be subject to wind drift, so for long range its not going to be used. If it won't replace both the .223 AND .308 it ain't worth the time and money.
I beg to differ on this one point...
A 62 grain .224" FMJ-BT similar to the M855 NATO load that is in current use by the U.S. military has a BC of roughly 0.307. The 115gr FMJ-BT .277" bullet slated for use in the 6.8mm SPC has a BC of roughly 0.325. In other words, the 6.8mm SPC's bullet is just as ballistically efficient as the current .224" mil-spec bullet. The 6.8mm SPC should have a MV of roughly 2,800fps in with the military loading, compared to the 3,100fps of the M855 green tip ball ammo, so the trajectory will not be quite as flat, but at the typical engagement ranges of modern warfare the slightly steeper long-range trajectory is irrelevant. If ranges become extended, it's a simple matter to make a quick elevation adjustment to bring zero the rifle. Of course, if the enemy is far enough away to need to adjust the sights with either cartridge, they are far enough away to call in a fire mission and let arty blow them SOB's apart first, then close with the enemy using fire-and-maneuver to kill whoever is left.
The biggest difference, and benefit, is that the 6.8mm SPC makes a bigger hole, which should mean the terrorists will get to meet Allah a little sooner...and the sooner the better!
Mike