Well, I wish I could provide torque specs and blah-de-blah to scientifically solve the conundrum, but I can't. I will only tell you what has worked for me so far.
First of all, all of my Rugers have a stable bedding surface on the stock face that the lug seats against. I tighten the front action screw REALLY tight. (sorry to bewilder you with highly technical terms
) Then I tighten the rear screw tight, then snug up the mid screw a bit.(the front trigger guard screw)
I think that most Rugers that have been out of the stock have likely been subjected to improper torque sequence, thus allowing the action a certain amount of displacement that could significantly affect accuracy.
All of my Rugers shoot best about .010" to .015" off of the lands. (In fact, the 6mm284 is absolutely intolerant of jam)
Hope this helps.