In each rifle, the Federal load with the 150-grain Nosler Partition was the best-shooting, by a noticeable margin. Three-shot groups in both rifles averaged 3/4" or less, at quite high velocities.
My 7 mm WSM is a Model 70, and it really likes the Federal Premiums with 160 partitions, as you say, with quite high velocities. I've quit handloading for it as a result. The Federal Premiums don't shoot as well in the .270 WSM though. Might have something to do with the chamber, there's a big difference shooting new brass vs. once-fired with the same bullet and load combos.