Various embodiments provide apparatus and methods for melting and introducing alloy feedstock for molding by using a hollow branch having a constraint mechanism therein. In one embodiment, a hollow branch can extend upward from a cold chamber that is substantially horizontally configured. The hollow branch including a constraint mechanism can be capable of containing an alloy feedstock for melting into the molten alloy in the hollow branch and introducing the molten alloy to the cold chamber for molding.