Im working on a 450 bushmaster barrel for my savage.
You WILL be able to push the SOCOM to a lot higher levels out of a bolt action. Should be very interesting.
Depending on what you intend to hunt, you might consider going witha .452 1 in 36 twist barrel. I personally feel that the hornady FTX bullets offered cover about anything you could care to hunt in the US. They are more widely availible and less expensive than most .458 bullet offerings. At least thats been my finding.
Just my 2 cents. Be sure and keep us posted whichever ay you go.