Most Mannlicher style stocks have the center portion of the forend "hogged out" to relieve the barrel, and then then last 1.5" or so at the muzzle are pressure bedded with the end cap securing the barrel to the stock... in my experience this does not adversely affect accuracy, in fact a couple of my most accurate rifles have been full stock rifles. On an individual basis it might affect the accuracy, just as any stock can ... of my three dozen or so fullstock rifles, only two required accurizing that may have been attributable to the forend... and these were dealt with in the same way that I would a regular stock.