Pillar bedding is another method to try and isolate the action from the stock.
Wood changes shape and size with moisture content changes, and no finish can effectively stop the movement of water vapor in and out of wood.
Some of the 'epoxy' type finishes can come close, but most are not thick enough or applied uniformly enough to stop all movement of water vapor.
Localized movement can be worse than uniform movement
If the material of a non-wood stock is affected by moisture content it can also move.
Any movement can produce changes in loads on the action and effect its behavior under the stress of firing.
Wood touching a barrel is well known to alter the vibration patterns in the barrel.
Wood exerting force on the action may change its vibration patterns.
Last edited by brickeyee; March 19, 2012 at 11:52 AM.