I have a .270 WSM and a .270 Weatherby with equal length barrels, I think the .270 WSM is pretty underwhelming compared to the Weatherby round. I've seem some pretty good numbers put forth by others, but my rifle won't achieve them. The WSM in question does not get advertised velocity with factory ammo either. It's a sample of one either way.

"The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants." TJ

"All that is necessary for the triumph of evil is for good men to do nothing". EB