Beg to differ, the substantial increase in performance we gained in the zuni isnt an isolated case. Some of the older folks here may be familiar with the early bellanca cruisair series of aircraft. The bellanca cruisair when new would cruise at 150 mph on 150 hp franklin engine. This is for a four place built like a brick ****house wood and tube aircraft of the late 1930's.. Part of the efficiency of guiseppe bellanca's designs was based upon a fuselage planform that was in itself a lifting surface. As for the 50 cal analogy, definitely applicable to the trans-sonic and sonic regions of the flight envelope but not the most efficient shape for subsonic flight.