Taylorce, I wasn't clear when I asked the question above.
I was thinking both cartridges with 1:8 twist barrels. Like Hudge and TRexF16 did with their WSM's.
Gotcha, my mistake. All I've really compared is 150 grain load data, and the WSM is faster by less than 100 fps on average. The 6.8 is almost identical but .08" shorter than the WSM case. I don't know what that equates to case H2O capacity.
I'd imagine the WSM retains that speed advantage with bullets needing a faster twist.
