Protective body armor

Consider how classes differ:

• 1st protection class . Must withstand shots with 9×18 caliber cartridges, bullet 57-H-181s, bullet weight 5.9 g, firing distance 5 meters, speed 335 m per second. Also 9x19mm LugerParabellum, FMJRNSC bullet, weight 8g, distance 5 meters, speed 400 m / s
• 2nd protection class . Caliber 7.62x25mm, bullet 57-H-134s, weight 5.5g, distance 5m, speed 430 m / s
• 3rd protection class . Provides protection against bullets caliber 5.45×39, bullet 7H6, weight 3.4 g, distance 10 meters, speed 910 m / s. And from 7.62×39, bullet 57-H-231, weight 7.9 g, distance 10 meters, speed 730 m / s
• 4th protection class . Used for protection against bullets 5.45×39, bullet 7H10, weight 3.6 g, distance 10 meters, speed 910 m / s. In addition, it must protect against caliber 7.62×54, bullet 57-H-323s, weight 9.6 g, distance 10 m, speed 850 m / s
• 5th class of protection. Provide protection against armor-piercing incendiary cartridges caliber 7.62x39mm, bullet 57-B3-231, weight 7.4g, distance 10m, speed745 m / s. And SVD 7.62×54, bullet 57-N-323s, weight 9.6 g, distance 10 m, speed 850 m / s
• 6th class protection . Holds an armor-piercing bullet caliber 7.62×54, bullet 7BZ-323, weight 10.4g, distance 10m, speed 860 m / s.