The one key thing a bullet causes is not just a hole, but a shockwave. A knife, arrow, or any pointy object can cause a hole, but a bullet will cause massive internal pressure gains once it enters the body by reaching mere shockwave alone. The shockwave alone in a bullet has been known to fracture bones in some patients without actually physically touching the bone. The term “permanent cavity” is the area where the shockwave expands upon entering the body, obliterating the organs, tissue, and thin blood vessels, and arteries within the human body. Take a .380 hollow point for example. Doesn’t seem like a large round at all by terms of what size bullets used in the Civil War, but the .380 hollow points cause more damage now than they would have back then, because of the changes in powder, charge, and the hollow point design. A soldier would have been lucky to have a through, and through wound considering they’d have to first fish the bullet out of their body. Take into consideration that the bullet is traveling at upwards of 1200fps in a musket alone, and the sheer speed, and impact on the human skin alone causes the outer tissue to ripple from the shock wave, and as the bullet enters it only gets bigger. I worked less enforcement long enough to see the ugly side of gunshot victims, and the shear magnitude a modern handgun bullet would do to someone’s body, and have seen the effects of hunting rifles as well. The main causes of death in patients who suffer gunshot wounds is hemorrhaging, blood loss due to severed artery, shock to vital organs from the production of the shockwave, embolism, or even asphyxiation due to blood entering the lungs.
I know the answer you want is: are all mushroomed bullets ones fired into someone’s body?
The answer is more harder to answer when dealing with bullets that are 150+ years ago due to the fact that we’ll just never know unless you find some supporting evidence, ie: found next to many other ones along with pieces of surgical equipment. With the advent of modern science finding which bullets entered the body of a modern gun, which gun fired it, and who it belongs to is a lot simpler now due to the fact that modern firearms have rifling grooves that cause small striations in the bullets. After 5-6 shots a microscopic amount of the rifling is changed due to the pressure of the bullet, exploding gases, and the bullet itself twisting its way down the barrel.
I was a Crime Scene Analyst, under the main Major Crimes unit, and Homicide Unit, worked under the Chief Crime Scene Analyst, and Luminol, hydrogen peroxide, and sodium hydroxide was used on crime scenes we worked, I was no chemist, but bullets nowadays that are shot in to someone show signs of it via blood staining, tissue, and other bodily fluids. Now if a bullet from 150+ years ago could be found in an area of where there wasn’t the possibility of moisture, and other contaminants Luminol would be a possible way to determine if it hit a human body, but it’s still not definitive. Sorry for the long post, but the forensic science behind bullet wounds, trace evidence, and other things that would result in injury or death from firearms is something I’m good at determining, but like I said unless found in the same location of a known hospital, or found along with a bone saw, and other bullets it would be easier. Sadly harder mud, and dirt can cause the same mushroom effect, and make it hard to tell what it hit.
