Heat capacity and bulk susceptibility measurements show KOsO4 to be an antiferromagnetic with modest Neel temperature but there is no indication of magnetic scattering in our preliminary Neutron diffraction data. Our currently hypothesis is that this is a consequence of the weak magnetic form factor for the OsVII cation, and that establishing the magnetic structure will require higher quality data than achieved using the constant Wavelength diffractometer Echidna. We note that the strongest magnetic peak in the neutron pattern of the isostructural and isoelectronic oxide KRuO4 has only 0.25% the intensity of the strongest Bragg reflection. We anticipate the higher quality data available using WISH will enable us to understand the magnetic structure of this oxide.