To evaluate bulk compressibility, synchrotron diffraction experiments were performed on each Mo 2-x W x BC composition under compression. A Diamonite T M mortar and pestle was used to grind the arc melted samples to a fine powder, mixing in 5% ruby powder and 10% platinum powder as pressure calibrants. The finest particles were isolated from the bulk powder through solvent suspension in methanol. This process was repeated on the isolated material to achieve an even finer particle size. Sample/Pt mixtures were loaded into a 45-60 µm diameter sample chamber which was laser milled into stainless steel gasket material after pre-indention to a thickness of ∼40 µm from an initial thickness of 250 µm. To achieve near-hydrostatic conditions, sample mixtures were gas loaded into the sample chamber with a neon pressure medium. High pressure conditions were achieved using a symmetric DAC with 200 µm diameter flat culet diamond anvils.