Preliminary results of producing Cu–Y–Ba metallic precursors to high Tc superconductors by high energy ball milling are reported. Mechanical alloying of Cu, Y, and Ba powders (various stoichiometries) produced either amorphous, mixed crystalline/amorphous, or fine grained crystalline powders, as shown by their x-ray spectra. None of the powders exhibited flux exclusion down to a temperature of 1.4 K. The YBa2Cu3 precursor consisted of a mixture of crystalline phases. After being pressed into a pellet and sintered, it was found to be superconducting at liquid nitrogen temperatures.