Autobahndriver, I heartily agree with all your points. However, if you want to be technically accurate, we don't yet have the tests that PROVE your assertion: "The 6.8 SPC and 6.5 Grendel have identical terminal performance at short range."
I've long argued that I see no theoretical or technical reason why a target would ever be able to tell the caliber difference of ONE-THIRD of a MILLIMETER, but to be fair I don't have the test results to back it up. Not that gel test results are ultimately conclusive anyway; they don't even account for hitting bone, for example. They are a great tool in the ballistician's lab, but they're only part of the picture.
But the good thing about the 6.5 Grendel is that it uses 6.5 bullets just like many other traditional 6.5 cartridges. There's no magic there. We've got a very long history, over 100 years, of knowing what 6.5-caliber bullets can and can't do. They've been used for hunting almost everything, and I say that if they're good enough for moose they're good enough for terrorists.
About the only thing the history of 6.5 bullets doesn't show us is the reduction in velocity in going to the smaller PPC case versus a more traditional 6.5 Mannlicher or, of course, the 6.5 x 55 Swede. But, on the other hand, we have almost no historical record of performance, that I'm aware of, of 115-grain 6.8 bullets at slower velocities than the .270 Win typically gets. I'm not saying the 6.8 is a dog; I say terminal performance is practically a wash with the 6.5. But I do think it will be borne out that the 6.8 does trail behind in external ballistics and penetration of barriers.
The bottom line is that I'm with you. Not adopting the 6.5 Grendel in favor of the second-place 6.8 SPC would be another bureaucratic/political blunder akin to the military's $600 toilet seats.
John
