The U.S. Justice Department researches and develops standards for body armor performance.
The current N.I.J. (National Institute of Justice) standard started in 1987 and the most recent version published in July 2008 is the main standard used today. It covers aspects of design, manufacturing and ballistics for hard and soft body armor. Armor that has been submitted to NIJ for testing and has received certification of compliance can be warn with the confidence that it will perform to the stated rating.
There are 5 threat levels for ballistic body armor but for most applications the two levels that are significant for soft body armor are Level II and Level IIIA. Level III and IV are for hard body armor plates designed to protect against projectiles at rifle speeds.
Keep in mind, the rounds used in testing are faster than normal factory rounds which give all NIJ tests an added level of assurance that the designated calibers will be stopped within the guidelines of the standard. In other words, NIJ certified armor should be slightly over tested in order to insure safety and confidence.
Threat Level II:
Level II body armor is tested with and certified to protect against high velocity 9mm FMJ and .357 Mag JSP rounds as well as lesser threats. The vast majority of hand gun and ammunition sales would be stopped by this level of armor. Lesser threats include but are not limited to .22 LR, .380, 9mm, .40 S&W, .45 ACP normal factory rounds.
Threat Level IIIA:
Level IIIA body armor is tested with and certified to protect against .357 Sig FMJ RN and .44 Mag SJHP rounds as well as lesser threats. This is the highest handgun rating for body armor. Lesser threats include but are not limited to .22 LR, .380, 9mm, .40 S&W, .45 ACP, .357 Mag normal factory rounds. Our level IIIA soft body armor has received special threat testing against many exotic and “hard-to-stop” rounds such as 9mm SXT, .40 cal SXT, .357 Sig GDHP, 7.62x25mm (Tokarev), 5.7x28mm SS/195 LF, 5.7228mm SS/197 SR and 9x19mm Liberty Ammunition Civil Defense rounds. Independent lab results will be posted soon.