6 to 9mm is 1/4-1/3". That's pretty outstanding accuracy at 100 meters, so I'm not really sure what you more you expect to gain unless you're shooting a full-blown competitive benchrest setup. I'd take that 1/3" and be happy knowing that your rifle shoots better than 99.9% of all rifles out there.
As for your question, you might want to try searching the Sako website (
www.sako.fi). I think that they have manuals for some of their guns available for download, so you could try there.
Mike