Great info. Thank you.

For the record, reason I was thinking 308 is a parent case is because you can make 6.5 creedmoor from it. Doesn't mean its parent case though. Takes a lot of annealing to bump that shoulder back so far.

I would also need to consider if it will work in an AR10. I plan on building one maybe next year late summer or winter. Ive been looking at 6.5 creedmoor but Ive heard 6mm has no recoil and extremely accurate. So if I have one chambered in my bolt gun, I might as well save pennies and use the same caliber for the AR so everything is already there for reloading.