One thing I've noticed is that the ACW has much less lethal musketry than earlier wars. A typical mid or late war battle produces 6 or 7 wounded for every man killed, whilst early war battles and older Napoleonic battles often produce 2 or 3 wounded per man killed. There is an explanation. The new rifled small arms in use are in fact lower energy than the old smoothbore muskets. To wit I calculate:
Figure 1: kinetic energy of an M1842 smoothbore round (.65 ball, ballistic coefficient 0.095, muzzle velocity 1,500 fps) vs an M1861 rifle-musket round (.5775 Burton ball, ballistic coefficient .160, muzzle energy 963 fps).
My *very* rough calculations suggest that roughly 90% of those shot with a Springfield or Enfield type weapon survived the wound, which seems to be an improvement over the maybe 75% who survived smoothbore balls. The problem is that our statistics are skewed, as those killed outright never got to the hospitals to make it into the statistics (the same happened to the killed and wounded in the Crimea, with a doctor reporting only 6% of those he saw were shot in the chest (ref)).