Most people find it very difficult to kill or even contemplate killing another human. In many cases, this reluctance isn’t even driven out by military training. From Patrick Macfarlane at libertarianinstitute.org:
In 1996 Lt. Col. Dave Grossman authored “On Killing,” a seminal study on “the psychological cost of learning to killing in war and society.” In it, Grossman documents the unheralded history of man’s inherent resistance to taking fellow human life. This history is so concealed that some, such as philosopher-psychologist Peter Martin have called it “a massive unconscious cover-up.”1
Indeed, despite the near universal glorification of combat across human society, the threads of this hidden truth are everywhere.
For instance, Grossman recites a well-documented study of Prussian infantry accuracy and firing rates. This study found that, using smoothbore muskets, Prussian infantry scored “25 percent hits at 225 yards, 40 percent hits at 150 yards, and 60 percent hits at 75 yards when firing at a 100-foot by 6-foot target.”
[t]hus, at 75 yards, a 200-man regiment should be able to hit as many as 120 enemy soldiers in the first volley. If four shots were fired each minute, a regiment could potentially kill or wound as many as 480 enemy soldiers in the first minute.2
With these established accuracy numbers, casualty rates in that era should have been near one hundred percent, given that, for instance, the average American Civil War engagement took place at “thirty yards.” Conversely, death rates in that war were as low as “one to two men per minute.” Engagements lasted for hours.3 An examination of accuracy rates across a number of contemporary conflicts corroborates these results.4