As the historian Shelby Foote said, “The reason the casualty numbers were so horrific is because the weapons were way ahead of the tactics.”
I read where smoothbores were effective out to about 100 yards and if hit, the ball just plowed through, breaking any bones encountered. The rifled muskets could hit a man on horseback at 500 yards and if you aimed in the center of the crew serving an artillery piece at 1,000 yards, you'd hit somebody. The Minie ball mushroomed on impact and shattered bone clear up to the joint, which is why there were so many amputations.