I also recomend the 180 Bergers. I did not try the 168's. Just went from 162 a-max's to the 180's.
They stabilize in my 1:9" 24" Broughton 5C just fine.
I'm running them at 2900 with Retumbo, but have not tried H1000. I started load development with 4831, then Retumbo and found a .3" load with Retumbo, so stayed with it.
My fear with the Bergers was close range expansion or fragmentation. That was not an issue afterall. I shot a cow elk at about 100 yds through the boiler room last year. The results were near perfect to me, with a 2" exit and no meat loss.
I am happy with the chambering. How happy, well I'm building another 7WSM in a lightweight configuration. It seems to be the right balance of power for the game I hunt.
What are the differences that make the 7-300 WSM
a better choice? Longer neck?