A disc of a gas turbine engine system with particular retaining ring placement and engagement implementation are provided. For example, the disc includes a disc bore including, a groove formed on an axially extending surface of the disc bore, wherein the groove includes a forward surface that extends radially into the disc bore to a groove floor that is cut into the disc bore and extends axially to an aft surface that extends radially outward to at least the axially extending surface of the disc bore, and a scallop formed along at least one surface of the groove, wherein the scallop is configured to provide a flow path, and a disc web that extends radially outward from the disc bore, relative to an axis of rotation of the gas turbine engine.