I struggle with the concept of a 1-8 twisted 30 cal.
The latest research is that 1:8 twist is a good thing even for 308 - because it helps the bullet expand by the rotational force, and improves terminal effects. Also, there is some evidence that it helps the bullet survive the transonic boundary and increases the ability to shoot much longer range.
So I would use 1:8 or 1:7 even for full power 308.
