All sorts of cyanoacrylate adhesives. Get one intended for woodworking.
As GEF suggested, cut a groove across the crack on the inside of the stock, and epoxy in a piece of threaded rod. Something 1/16"-3/32" in diameter is all that is needed. This physically locks the crack closed, in addition to the adhesive worked into the crack.
As GEF suggested, cut a groove across the crack on the inside of the stock, and epoxy in a piece of threaded rod. Something 1/16"-3/32" in diameter is all that is needed. This physically locks the crack closed, in addition to the adhesive worked into the crack.