Yes, to go to either WSM or SAUM you will need to open up the bolt face to magnum case head diameter. The .308 has a .473 case head diameter and the WSM and SAUM have .532.
If I had to chose I would take the WSM, it is more popular and even Remington is chambering their new SPS in .300 WSM. I believe it holds a tad bit more powder also (if you are a hand loader).
MEL
If I had to chose I would take the WSM, it is more popular and even Remington is chambering their new SPS in .300 WSM. I believe it holds a tad bit more powder also (if you are a hand loader).
MEL