If it is one of the older tang safety Rugers they have been out of production since the early 90's. At that time Ruger did not make their own barrels, but purchased them from different outside sources. Some rifles came with quality match grade barrels, others got 2nd rate, inaccurate barrels. Accurace was all over the place on those older versions.
Ruger started producing their own barrels when they went to the 77MK-2 and accuracy has been consistently better since. If your gun is a newer version, then contacting Ruger MAY be of some help. On an older gun, good luck.
Ruger specifically says not to free float their guns. I know of some guys who have done so with mixed results. It seems to help on some, not at all on others.
One quirk of Rugers is the angled action screw. It seems that if it is not tightened correctly it will have a bigger effect on accuracy than any other design. Most people report the best accurtacy by 1st loosening all 3 screws. Then tighten the angled screw as tight as possible. This pulls the action down and back into the stock. If you don't loosen the other screws first they don't allow the action to move properly. Then tighten the rear screw almost as tight. The middle screw should be just tight enough to not loosen and fall out.