It is impossible to resist at close range. Body armor is divided into two categories, one is full soft body armor (weaker protection capacity) and the other is reinforced/composite body armor (stronger protection capacity). Fully soft body armor, usually made from high-performance fibers (such as nylon and Kevlar). The principle is that when a bullet/fragment hits this kind of fiber layer, its huge impact force will be consumed when the fiber layer is stretched and sheared. At the same time, the fiber layer will absorb the impact force generated by the bullet/fragment. fragment spreads to areas beyond the point of impact, absorbing the impact of bullets/fragments. Fully soft body armor can withstand bullets from pistols and shotguns or fragmentation attacks from explosives such as grenades, as well as attacks at longer ranges.gue carried with automatic rifles (not at close range).
The Reinforced/Composite Body Armor is based on a fully soft body armor with additional hard materials such as metal, ceramic and high performance composite panels. The bulletproof principle of this type of composite body armor is that when a bullet hits, it first contacts the metal plate, ceramic plate or composite material plate of the body armor ( equivalent to the first line of defense at the time of contact). the bullet and hard plates made of high-quality bulletproof material may have cracks, which consumes most of the energy of the bullet. As a second line of defense, soft bulletproof materials absorb and diffuse the remaining energy of the bullet and act as a buffer, thereby achieving the purpose of bulletproofing. Reinforced/composite body armor canresist more powerful weapons, such as automatic rifles.
There are many standards for measuring the protective capabilities of body armor, but the most common standard is the NIJ standard.
Level IV (Level 6) can withstand a muzzle velocity of approximately 887 meters per second (projectiles weighing 10.8 grams). It has bulletproof inserts, crotch protectors and neck protectors. Basically the same as the image below.