Excuse my poor english, I am from Alabama
This type of "tuning" is what those of us which shoot Ruger #1's have done for many years. The #1 has a forestock that is attached by a screw to a rod that comes out of the action and is paralell to the barrel and just under the barrel. The very tip of the forestock commonly is in contact with the barrel. By tightening or loosening the screw you can apply different amounts of upward pressure on the barrel. This will allow you to "tune' the #1 from 2.5 MOA groups to about 0.5 MOA groups.
There is a commercial device sold for #1's that also works the same as the foreend screw.
While barrel contact devices will or may work to an extent they are very, very, very, sensitive to barrel temperature and as the barrel warms up, group size will grow begin to string badly.
If you believe that your barrel may be helped by one of these devices you can test it out by simply getting your calipers out and finding different thickness of shims to insert under the barrel at the end of the forestock and go to the range and shoot and see if upward pressure helps. Sometimes it does and sometimes it doesn't.