You seem hung up on using a short cartridge in a long action. If that is indeed the case (pun intended) then why ask?
You will never beat the BC of the 180 7mm bullets but can match the 168s with the 6.5 140s.
With a long action, I would suggest a 6.5-284 or 6.5-06[AI] etc.
If you are stuck on 7mm bullets they a 280. As you go bigger and faster, recoil will increase.
I love the 7mm-08 but am trying to give you an option for the long action
