All of the really experienced stock people I've talked to says it simply isn't necessary. I've got two that work fine w/o them. Had a 3rd which I sold for other reasons. Simply not necessary with a well built synthetic.
Barsness, in one of his latest books, discusses this at lenth. It seems tha the old military Mausers had pillar bedding. Apparently necessary because their stocks were made from indifferent wood that often became oil soaked. E
