We had to learn the penetration of arrows for ourselves. When we first started hunting deer, we feared that the wounds might be insufficient to cause death. We soon found that an arrow lodged in either cavity of a deer meant sure death, and that if unmolested such a wounded animal traveled but a short distance and lay clown. Chest wounds, because they are held open by the shaft, cause a collapse of the lungs, and fatal asphyxia. A bullet kills by shock, an arrow by hemorrhage.
Our arrow heads are sharpened with a fine file, which gives them a serrated edge. This is better for cutting animal tissue than an edge made with a whetstone. The concoidal edge of an obsidian or flint arrow head cuts even better than steel.
To determine this I selected two arrows the same weight and feathering and having heads the same size. One of these heads was obsidian, made by Ishi. the last Yana Indian; the other was steel. also made by Ishi. A box was then constructed with two sides of fresh deer skin tacked in place. The space between was filled with beef liver, simply to give a homogenous animal substance. The skins were four inches apart. Shooting at this with a weak thirty pound bow at ten yards, the steel headed arrow universally penetrated a distance of twenty-two inches. The obsidian arrows averaged a penetration of thirty inches, or about twenty-five per cent better.
These fragile tips, however, are not suitable for hunting, where one misses one's mark or strikes a bone. The steel heads cut through ribs with no difficulty, and even sever the smaller long bones of game.
The blow of an arrow may be compared to the striking force of a hunting knife, only it is greater, because the power transmitted through the bow is that of the biceps muscle, while that of a knife thrust is from the triceps, a muscle in the back of the arm and not so strong.
Every blood vessel in the path of an arrow is severed—the hemorrhage is tremendous. I shot a buck at sixty-five yards. The arrow went completely through the animal's chest, cutting the aorta, and flew twenty yards past the deer, sticking in the ground. He died instantly. We have killed eight deer with the bow and only lost one wounded.
At first we had misgivings about our ability to shoot through bear, but we soon found that we could shoot completely through black bear, and almost as readily through large grizzly. In our last hunt in Wyoming we killed five grizzly bear with an arrow apiece. Three of these were heart shots and two were lung shots. Death was immediate in all but one.