Bulletproof vests, also known as bullet-resistant vests or ballistic vests, are worn to protect police officers, soldiers, emergency medical technicians, paramedics and rescue teams from bullets, shrapnel and knife attacks. They are made by DuPont of tightly woven or laminated fibers known as Kevlar 29 and are rated by the National Institute of Justice. Choosing the proper protection is done by assessing the threats most likely to be faced.
How Bulletproof Vests are Rated
The more layers of ballistic fiber used, the more protection a bulletproof vest is able to provide. Vest levels correspond to the thickness of the vest. They are determined by testing the vest’s ability to stop penetration and minimize the blunt trauma that a body suffers from a bullet’s impact. Standard test rounds are used to test vests, although tested vests are able to stop many other comparable rounds and lesser threats.
Level I vests are tested for .38 Special ammunition at 850 feet per second and .22 ammunition at 1,050 feet per second. They offer the most basic protection and are made of one of the first ballistic fibers used. Level I vests only stop fragmentation and low-velocity pistol ammunition. They are not recommended for pistol ballistic protection but can be used for riot gear or for playing paintball.
Level II-A vests are usually 4 millimeters thick and are tested for lower-velocity 9 mm full metal jacket ammunition at 1,090 feet per second and .357 Magnum jacketed soft point ammunition at 1,250 feet per second. They offer greater protection and are the minimum recommended vests used for most threats encountered on the street. Because this is a thin vest, the wearer would sustain more blunt trauma injury than with a Level II or III-A vest, but it is easily concealed and comfortable to wear.
Level II vests are usually 5 millimeters thick and are tested for 9 mm full metal jacket ammunition at 1,175 feet per second and .357 jacketed soft point ammunition at 1,395 feet per second. They offer blunt trauma protection while still being comfortable to wear and easy to conceal. Level II vests are often recommended when the wearer needs to conceal the vest, when vests are worn for long periods or when there is a lot of movement. They are often worn by police officers. Level II vests are also able to handle the blunt trauma of higher-velocity rounds.
Level III-A vests are between 8 to 10 millimeters thick and are tested for 9 mm full metal jacket ammunition at 1,400 feet per second (the velocity of a submachine gun) and .44 Magnum Lead Semi-Wadcutter ammunition at 1,400 feet per second. They provide the highest blunt-trauma-protection rating available for concealable ballistic vests. Level III-A vests are able to protect the wearer against most handguns and all weapons tested on lower-level vests. These vests are slightly thicker, stiffer, heavier and more expensive. They are best used in high-risk situations to cover more of the uncommon or unusual threats, such as explosions and grenade attacks.