A rheo-casting container for containing a charge of semi-solid metal alloy includes an elongate body defining a side wall of the container, a mouth at a first end of the body, an opening at a second end of the body, and a closure member to close the opening. The closure member is configured to be displaceable along an interior volume of the body from the second end towards the first end to display a charge of semi-solid metal alloy contained in the container. The closure member is of a metal alloy the same as or similar to the semi-solid metal alloy for which the container is to be used and has a melting point which is not less than the temperature at which the metal alloy is to be introduced into the container.