New wind tunnel data has been obtained to investigate the effects of tip bluntness and angle of attack on boundary layer transition on slender cones. The rearward displacement of transition due to tip bluntness and the maximum displacement of transition are reasonably well understood and explainable primarily on the basis of a reduction in local Reynolds number due to pressure losses across the bow shock. The rapid forward movement of transition observed on the cone frustum is a mystery and will be studied further in future experiments. The observed rapid movement of transition from the sphere-cone tangency point to the subsonic region of the tip is compatible with stability analysis and has been observed by several experimentalists. The transition movements obtained on the sharp cone at angle of attack were compatible with both theory and other experiments. The movements of transition on blunt cones at angle of attack remains poorly understood. The present results appear reasonable; however, since many different trends have been observed in transition experiments and since there is little guidance available from stability analyses, additional confirmation of these transition trends are needed. (Author).