bullet resistant

Bulletproofing is the process of making something capable of stopping a bullet or similar high velocity projectiles e.g. shrapnel. The term bullet resistance is often preferred because few, if any, practical materials provide complete protection against all types of bullets, or multiple hits in the same location. Bullet designs vary widely, not only according to the particular firearm used (e.g. a 9x19mm Parabellum caliber hollowpoint handgun cartridge will have inferior penetration power compared to a 7.62x39mm rifle cartridge), but also within individual cartridge designs. As a result, whilst so-called “bullet-proof” panels may successfully prevent penetration by standard 7.62x39mm bullets containing lead cores, the same panels may easily be defeated by 7.62 x 39 mm armor piercing bullets containing hardened steel penetrators. Bullet-resistant materials (also called ballistic materials or, equivalently, anti-ballistic materials) are usually rigid, but may be supple. They may be complex, such as Kevlar, Lexan, and carbon fiber composite materials, or they may be basic and simple, such as steel or titanium. Bullet resistant materials are often used in law enforcement and military applications, to protect personnel from death or serious injuries. There are various mandatory tests which items must pass before they can be classified as bullet-resistant. These tests specify the detailed characteristics of bullets which the material or object must be resistant to. For example, the United States National Institute of Justice standard 0104.04 [ ] for bullet-resistant vests specifies that a Type II vest must not deform clay representing the wearer’s body when hit by an 8.0 g (124 gr) 9 mm caliber round nosed full-metal jacket bullet travelling at up to 358 m/s (1175 ft/s); but a Type IIIA vest is needed for protection against the same bullet travelling at up to 427 m/s (1400 ft/s). In both cases, the vest is not required to protect against a second hit within 51 mm (2 inches) of the first.