Described herein is a feedstock including a core comprising BMG and a sheath attached the core. The sheath has a different physical property, a different chemical property or both from the core. Alternatively, the feedstock can include a sheath that encloses one or more core comprising BMG. The feedstock can be manufactured by attaching the sheath to the core, shot peening the core, etching the core, ion implanting the core, or applying a coating to the core, etc. The feedstock can be used to make a part by injection molding. The sheath can be used to adjust the composition of the core to reach the composition of the part.