Magnetization measurements on cubic Ba0.6K0.4BiO3 crystals, approximately 5µm in radius, have been obtained using a recently-developed electrodynamic force balance technique. The onset of flux entry in an external filed H is marked by a pronounced deviation from a linear magnetization at a critical field H* c1 together with a noticeable reorientation of the crystal near H = 0, a reorientation caused by a field-induced torque on the remanent moment. The dependence of H* c1 on temperature is linear over the temperature range 7K≤T≤30K with a slope approximately a factor of three higher than published values. These higher values of H* c1 imply either intrinsically cleaner material with a reduced Ginzburg-Landau parameter K or higher surface critical fields. These results suggest that the intrinsic properties of high-Tc superconductors may be more accurately reflected in small crystals which are more likely to be of higher quality than larger crystals.