World War I armies couldn’t afford to arm all their artillery shells with deadly shrapnel:
Later came a startling revelation. In the 1930s a group of American technicians were setting up some shrapnel shells for a test and one shell exploded prematurely, peppering some of the people with the “lethal” metal balls. They all survived. Further investigation revealed that human skin, muscle and bone were far more resistant to the metal balls than wood boards. World War I combat surgeons, when questioned, remembered that they had never seen a penetration wound caused by shrapnel balls. There has never been much official note made of this very humane weapon during, or after war.