I shoot several 7mm's 7mm/08, 7 STW, and the mother of all the 7's the 7mm Allen Magnum, the 7 AM runs a 160 accubond at 3575 fps launched by 110 gr of very slow burning powder, the BC of the accubond figures out to .62, the 140 berger figures around .7 the trajectories between the 7mm AM and the 6.5 Gibbs are earily simular till you reach 800 yards. and the gibbs burns roughly 1/2 the powder of the big 7 AM.
The good thing about the 6.5 is that the high BC/SD bullets in the 264 can be fired with about any standard twist 6.5 barrel, to get into the really good 7mm bullets such as the 200 gr wildcat (BC of around .84) you need a specialized twist unless your shooting a large enough capacity case to get velocity to make up for the lack of spin.
RR