Plate armor is capable of stopping rifle rounds all the way up to 308 Winchester. The ballistic mitigation on plate armor is higher than the standard Kevlar soft body armor which is mainly designed to stop rounds from handguns.
People who don’t use body armor but have to wear one considering the situation they are in, it is very less likely that they would like to wear the body armor for one reason… "BECAUSE IT IS HEAVY!!". The lightweight body armor plates have to cover your back and the torso. A standard steel plate of 10"X 12"weighs 3.6 kg each. Therefore, about 7.2 kg weight rests on shoulders of an individual excluding the weight of the armored vest. And this is without the accessories such as ammo, water, magazines etc. all inclusive it may about 10-12 kg. Steel is the most reliable material for the most defense institutions such as US Army. That is how steel plates became an integral part of body armor.
However, there was a huge potential for a replacement of steel. There was a need to decrease the weight of the body armor as it was becoming a hazard in the swiftness of troops and other personnel. The replacement was supposed to high strength, it needed to be resilient and have a high degree of durability. When all these requirements were put together, a solution was invented, that is "Ceramic plates". This was the ultimate solution and it was widely accepted by the security personnel. They weigh even less than the half of steel plates and provide protection of NIJ level IV when put together with the armored vests.
The pursuit of lighter material continued. The point is, that the defense world is looking into a protection to weight ratio. Lighter and resilient is what the users look for. A new material called Dyneema was devised. These are the lightest plates which evolved. The plates on its own provide the protection from level III rating which means protection from 7.62 rounds which are used in high power automatic rifle rounds such as Kalashnikov.
The matter of concern when going lighter with the body armor plates is, the lighter you go, the pricier it gets. In another words, it is not "Pocket Friendly" to go lighter. The plate manufacturers are looking for solutions which are affordable, durable and reliable.
