Don wrote:
Curiously though, the Persian composite longbow was deadlier than the rifles used in the Napoleonic wars, so you really have to go up to WWI before you have a clearly superior technology in terms of raw power. The fundamental disadvantage being that it was so difficult to become a proficient longbowman, whereas you can train someone to be dangerous with a rifle in a few weeks.
During the Civil War, Henry repeating rifles appeared. With breech loading rounds and a high rate of fire, it would be hard to believe that any longbow would be superior.
Bullet wounds in the Civil War were also severe as they were high impact. An arrow just penetrates, but a big slug is devastating.