Poly finishes are for furniture and Kitchen cabinets NOT gunstocks, seal the bare wood with 3 or 4 coats of tung oil finish cut 50/50 with mineral spirits, put this on all bare wood action area, barrel channel, under buttplate outside of stock, etc. Then on the outside of the stock use several coats of the tungoil finished uncut rubbing with 0000 steel wool between every coat until the pours of the wood are filled, after the final coat of tung oil finish is applied and it is dry and the stock is rubbed down with the steel wool then apply 2 or 3 coats of "GB" LIN-SPEED, this finish can be applied and rubbed on with the heal of your hand, it will never get sticky like true oil does, you can actually rub the lin-speed until it is dry and it will never get sticky or tacky.
This type of finish will penetrate deep into the wood and offer more protection then the poly finished that just lay on top of the wood, if a poly finish is scratched moister can get into the wood through the scratch which has removed the finish from the stock in this area, if an oil finish is scratched the oil is still deep in the wood and moisture can not penetrate it, no need to wax the lin-speed finish, most waxes will look good but will also make the wood slick and harder to hang onto.