Abstract: A method in particular, comprises the steps of: (a) preparing a mold having a sprue leading to a substantially horizontally oriented runner, at least one riser extending from the runner, and walls defining a mold cavity in communication with the riser; (b) providing a shallow reaction chamber in the runner containing grain refining inoculant solids therein, the inoculant having a surface exposed substantially tangentially to the flow of molten metal through the runner; (c) pouring a charge of molten aluminum into the sprue with a sufficient pressure head to fill the cavity, the flow being substantially laminar through the runner; and (d) inverting the mold substantially immediately after mold filling and prior to solidification of the metal in the mold cavity.