I'm building a bookcase that will have plywood shelves seated in dadoes in the carcass. I plan to run screws into the end of the plywood to reinforce the glue joint. How should I size the pilot holes? Same as for hardwood? Larger? I'm a little concerned about the pressure from the screw delaminating the shelves. I'm using maple-veneered PureBond plywood, if it matters – I think (but am not certain) that the core layers are aspen.