Geez, wish I had some info. I absolutely adore my 6.8's.
Would LOVE to see the military go to a 6.8mm.
All I have is what I've heard.
As I understand it, when the military backed away from the 6.8mm, some forward operating groups held onto theirs, preferring the 6.8 over the 5.56.
That's all I got! LOL!
I will say this:
I don't know if they quit loading ammo for the 6.8, but if it ever hits the shelf, it doesn't stay long.