A short history of bulletproof vests from the 15th century to now
How does a bulletproof vest work? In many ways the idea of bulletproofing is older than bullets themselves. The notion that you could protect yourself against your enemy's weapons goes all the way back to the plate armor and chainmail of the medieval Knights. Further back than that, it goes back to the leather armor of Roman soldiers.
All this stuff was quite good against swords and battle-axes,
but the trouble was as weapons became more powerful and more accurate, body armor had to become tougher, and that meant heavier. By the time the first gunpowder musket had reached Europe it had all got a bit out of hand and the average weight of armor went up from 15 kilograms in the 15th century to something like 25 kilograms by the late 16th century. Eventually we arrived in the late 19th century, and the homemade armor used by Ned Kelly and his gang weighed around 45 kilograms! Which means that one outlaws energy was almost entirely consumed humping his own protective armor around.
Bulletproofing didn't need to be heavier, in fact, it needed to be softer and lighter. A bullet works by concentrating a great deal of energy. All the energy from its speed and its momentum into a very small point. That's why it can punch its way through apparently impenetrably surfaces like brick walls, and yet remarkably you can stop one with fabric. Some Koreans in the 1860s who realize that you had to increase the area that the bullet works against. Bullets intended for soft targets such as animals and indeed Korean soldiers, work by deforming on impact this increases the bullets area and allows it to do more damage. But it's also the bullets weakness as the Koreans worked out whilst being shot at by the French. They worked out how to make light weight protection from layers of folded cotton causing the bullet to deform just before it reached flesh and blood and causing the energy to be dissipated as it tried to force its way through the lower levels. When the Americans fought the Koreans quite soon afterwards they captured one of these
bulletproof vests and took it home for analysis. It worked and the idea quite quickly spread interestingly, Archduke Ferdinand of the austro-hungarian Empire was wearing one of these bulletproof vests when a nationalist Serbian assassin shot him in 1914. Unfortunately pay Archduke the assassin had the good sense to shoot him in the neck, thus starting the first world war. By the 1920s bulletproofing was positively hip in America where organized criminals adopted these gangster vests to protect themselves against rival gangs and of course the feds. This led to a sort of arms race with more powerful ammunition being developed to penetrate better bulletproof vests leading ultimately to the development of the notorious Magnum round. Providing protection against relatively slow handgun bullets isn't such a problem, it's reckoned that since 1973 over 3,000 US police officers have been saved from serious gunshot wounds by ballistic vests. The problem is trying to provide protection against high-velocity rifle rounds and bits of shrapnel as found on the back .fabric vests simply aren't good enough for this so modern body armor incorporates metal or ceramic plates as well. So now once again we come up against the age-old problem of weight a modern body armor vest can weigh as much as 15 kg, or if you remember exactly the same way that you medieval knight add-to-cart about.
