A bullet-resistant vest (body armor) - is an article of protective clothing that works as a form of armor to minimize injury from projectiles fired from handguns, shotguns and rifles . They are commonly worn by police forces, the military, and private security and civilians where legal. However, they are sometimes worn illegally, by those that the relevant government refuses to allow body armor. The term "bullet-proof" is a misnomer since these vests (depending on their armor level, see below) may provide little or no protection against rifle ammunition or even against handgun ammunition fired from a pistol-caliber carbine. The exception is the common .22 LR ammunition, which can usually be stopped by these vests even when fired from a rifle. These vests are usually protective against handgun ammunition fired from handguns (once again, depending on their armor level.) Vests may be augmented with metal (steel or titanium), ceramic or polyethylene plates that provide extra protection to vital areas. These hardarmor plates have proven effective against all handgun bullets and against specific rifles using specific ammunition. Normally referred to as tactical body armor, these types of vests have become standard in military use, as soft body armor only vests are ineffective against most military rifle rounds. The CRISAT NATO standard for body armor specifies the use of titanium backing. A vest does not protect the wearer by deflecting bullets. Instead, the layers of material catch the
bullet and spread its force over a larger portion of the body, absorbing energy more quickly and hopefully bringing it to a stop before it can penetrate into the body. This tends to deform the bullet, further reducing its ability to penetrate.
While a vest can prevent bullet wounds, the wearer still absorbs the bullet's energy, which can cause blunt force trauma. The majority of users experience only bruising, but impacts can cause severe internal injuries. This is considered to be unimportant by many, as it seems guaranteed any bullets or shrapnel with sufficient force to cause notable injuries would do more damage without the vest. Most vests offer little protection against arrows, ice picks, or stabbing knife blows. As the force is concentrated in a relatively small area with such bladed weapons, the tip of the object can push through the weave of most bullet-resistant fabrics. Specially-designed vests are available that can provide protection against bladed weapons, and sharp objects; they are often used in prison-guard vests. There are a variety of strategies to achieve stab and slash protection. Some materials like Dyneema® do offer considerable protection against these types of threats. This is important for the safety of law enforcement and prison guard personnel. History Firearms made their entry at the end of the medieval era. When many knights and nobles purchased their new breast plates, they wanted “proof” that the armor would protect them from early bullets. Armor makers would shoot the breast plates, and the resulting dent in the new armor was provided as evidence that it was “bullet-proofed”. The oldest bullet-resistant fabric vests were made from silk. At the forefront, the Rev. Casimir Zeglen of Chicago, IL developed a bullet proof vest made of silk fabric at the end of the 19th century. These expensive vests (often costing US $800 each in 1914, equal to $15,000 in 2005) were capable of stopping relatively slow rounds from black powder handguns. On June 28, 1914, Franz Ferdinand, Archduke of Austria, heir to the Austro-Hungarian throne was wearing such a silk vest, but nonetheless died when shot in the neck above the vest with a .32 ACP bullet fired by Gavrilo Princip using a handgun, starting a chain of events that quickly escalated into World War I. During World War I, the United States developed several types of body armor, including the chrome nickel steel Brewster Body Shield, which consisted of a breastplate and a headpiece and could withstand Lewis Gun bullets at 2,700 ft/s (820 m/s), but it was clumsy and heavy at 40 pounds (18 kg). Another type of body armor was designed in February 1918 by the Metropolitan Museum of Art. This breastplate was based on certain armor of the 15th century, weighed 27 pounds (12 kg), and was considered to be very noisy and restricting of the movements of the wearer. A scaled waistcoat of overlapping steel scales fixed to a leather lining was also designed; this armor weighed 11 pounds (5 kg), fit close to the body, and was considered comfortable.
bullet and spread its force over a larger portion of the body, absorbing energy more quickly and hopefully bringing it to a stop before it can penetrate into the body. This tends to deform the bullet, further reducing its ability to penetrate.
While a vest can prevent bullet wounds, the wearer still absorbs the bullet's energy, which can cause blunt force trauma. The majority of users experience only bruising, but impacts can cause severe internal injuries. This is considered to be unimportant by many, as it seems guaranteed any bullets or shrapnel with sufficient force to cause notable injuries would do more damage without the vest. Most vests offer little protection against arrows, ice picks, or stabbing knife blows. As the force is concentrated in a relatively small area with such bladed weapons, the tip of the object can push through the weave of most bullet-resistant fabrics. Specially-designed vests are available that can provide protection against bladed weapons, and sharp objects; they are often used in prison-guard vests. There are a variety of strategies to achieve stab and slash protection. Some materials like Dyneema® do offer considerable protection against these types of threats. This is important for the safety of law enforcement and prison guard personnel. History Firearms made their entry at the end of the medieval era. When many knights and nobles purchased their new breast plates, they wanted “proof” that the armor would protect them from early bullets. Armor makers would shoot the breast plates, and the resulting dent in the new armor was provided as evidence that it was “bullet-proofed”. The oldest bullet-resistant fabric vests were made from silk. At the forefront, the Rev. Casimir Zeglen of Chicago, IL developed a bullet proof vest made of silk fabric at the end of the 19th century. These expensive vests (often costing US $800 each in 1914, equal to $15,000 in 2005) were capable of stopping relatively slow rounds from black powder handguns. On June 28, 1914, Franz 
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