RE: What makes the 7400 SO in accurate?
I don't know. I have an old 742 in 30-06 that shoots 1 1/2" 3 shot groups at 100 yds. While my Sako L691 shoots 1/2" groups at 100 yds, the groups with the 742 are more than adequate out to 200 yards, which most of my shots are within. I haven't ever shot a 760 or 7600 so I don't know how that compares. If you want groups less than 1" at 100 yds, get a bolt action or single shot, not a semi-auto.