Pillar bedding gives you two points of support as said,that are metal ( usually) spacers taking up the space between the action screws and the threaded part they screw into ,this space is normally filled with stock material( wood),wood is compressible degrades with time and oils,grinds away each time you tighten the screw,you get the wood out ,replace it with metal and use epoxy to make the metal part of the remaining wood,the important part is using a release agent to keep from glueing the other parts together.
Action bedding is basically using gobs of glue in strategic spots to act as blocks to keep the action shifting left,right ,forward or back.bedding from the factory is often imperfect,or the wood has shrunk or been damaged or warped making the action either loose or stressed degrading accuracy from shot to shot,shooting squirrels may be fine but this makes a difference on targets at challenging ranges.
The same may be used to support the barrel either full bedded,free floated,or just I strategic points
Some bench rest guns have simply been glued permanently into the stock.regular rifle guys do not do this ,that's why release agent is important.
Last edited by shootrj2003; 03-27-2017 at 07:10 AM.