Barrels go through an "oscillation" when a rifle is fired. This oscillation is in the form of a figure eight, or what one might call a spiral sine wave. A lot of people believe, probably with good reason, that the seating depth of the bullet can be correlated to exit the muzzle at the point of where the axis of oscillation occurs. Meaning the bullet would exit the muzzle when the barrel is near the cross of a figure eight, making it a more consistent barrel position when the bullet exits.
If wood contacts the barrel and interferes with it's free oscillation then the whole theory is out the window, and accuracy will be degraded.
The theory of pressure points near the end of the barrel is simply another method of trying to "harness" or "reign in" the oscillation of the barrel to make for a more consistent barrel position upon bullet exit.
There are lots of conflicting arguments about which is best, and why. Most of the credible studies show that the free oscillation ie. free floated barrel is the best, and makes the most sense. But still it flys in the face of logic, why some rifles shoot best with a pressure point.
I simply have seen, in the rifles I own, that free floating makes them more accurate more often than not. Another point in favor of free floating a barrel, is that it is not affected by weather changes like a pressure point would be. So your rifles' zero will normally be more consistent.
