Went to the range today to try some of this torque tuning I've read about. Rifle is an old Savage 110 flat back with a Shilen prefit barrel.
Loaded up some rounds (338-06) that shot well in 85° weather using Barnes 210 TTSX and IMR 4895. Today temp was 52° and recent experience suggested that I shouldn't expect too much when there is a 30°+ temperature change.

I started with the front screw torqued at 65" # and the rear screw torqued at 15" #. I shot 3 rounds then increased the torque on the rear action screw by 5"#. Continuing in 5"# increments, it didn't take long to find the sweet spot, at 30"# on the rear screw the group shrank to 3/8" at 100 yards. All other torque values tested above and below 30"# produced poor results by comparison. I felt pretty good about the test but needed to verify the results.
Resetting the torque of the rear screw to 30"# and moving the target to 200 yards, I fired three more rounds. They were not as good as I had expected but did produced a group of 1/2 MOA. I'm guessing I was getting a little tired and wasn't holding my point of aim very well.
Long story short (or in summary if you prefer) it appears that torque tuning the action screws is well worth the effort. Can't believe I waited this long to try this, I must be a slow learner.