How does the Bullet Proof Vest Stop Bullets?
The bullets do so much damage because of the focused blunt trauma: they focus all the impact in a reduced area increasing the penetration rate. Bullet proof vests are designed to spread the energy laterally over the whole vest while deforming the bullet at the same time. The system works as the net of a soccer goal, lateral tension of the net spreads the energy of the impact and stops the ball without reflecting it (in most cases), the collision is completely inelastic. When hard protective pieces are added, the bullets might be deflected instead of stopped, but in the case of soft body armor it is extremely difficult to deflect a bullet, it will be trapped by the material and stopped. Even when the bullet doesn’t touch the skin, the impact can cause some internal trauma.