Steve,
The neck diameter of the Rugers is wildly oversized. Roger is right, measure a loaded round and get bushings .003 and .002 smaller but don't worry about Roger's statement
.....of course the ND of the chamber determins the correct ND of the loaded round... because while Rog is completely RIGHT, it doesn't apply to your factory rifle with it's oversized neck. I've owned all of the Ruger 6PPC USA's and you won't have to worry about nd of the chamber
Except that they'll split necks over time.
al
I took pics of the Sako last night and could get them uploaded and sent if you're still in the market.