Quick note on barrel orientation:
Pointing a barrel sideways would increase drag dramatically. A cylinder is one of the worst shapes possible. It has to do with the flow staying attached longer creating greater a more powerful area of low pressure behind the object. Vortex shedding and all that. You'll note that cars almost all have a bluff profile at the rear with a defined break instead of rounded rear ends. Obviously a teardrop profile is superior, but a long tail doesn't work in many applications.
A cylinder has the equivalent drag of a streamlined section ten times as large. Hence why early biplanes are so darned slow.