Flaws in the NIJ Level Rating System
For years, the NIJ published standards have been adopted by manufactures to categorize their product and put authority behind a vest that is otherwise yet unproven.
In achieving their objective, testing different models of ballistic armor under standard conditions to determine pass/fail, the NIJ has certainly succeeded. Most people in the armor market typically shop by NIJ level first and then by individual model. While this simplifies the buying process for the consumer, it creates many holes in the armor market and sometimes provides dis-incentives for manufacturers to produce the most effective armor possible.
Because the NIJ rating system is so widely used and accepted, it became inevitable that manufacturers would design products specifically around passing a certain Level of certification. The NIJ rating system is not simply rough categories for various levels of protection, rather it is a published, meticulously tuned routine of ballistic testing that serves as the “rulebook” for manufacturers. Each certification level has specific ballistic and “other” (Environmental, physical shock, abrasion, ect.) requirements that a vest must endure in order to pass. Just as in NASCAR, Formula One, the NFL, or any other competitive environment it is in the specificity of the rules and procedures that one can find advantage in. While it may be unfair to claim that manufacturers’ “game” the testing procedures in order to maximize the certification level per cost of manufacture. However, it is only rational to assume that most manufacturers make plates to minimally pass a certain NIJ level using the least, cheapest material possible.
The NIJ does not officially recognize the Level III+ designation, but it is common in the industry because there exists a need for such a level. Makers of rifle plates were not satisfied with the large gap between Level III and Level IV, which necessitates defeating 30-06 AP rounds. AR500 steel based armor, regardless of its thickness or extraneous coatings cannot defeat such a round due to a limitation in the material itself. However, AR500 steel is extremely effective in defeating even large caliber standard loadings and an almost infinite number of lesser rounds. Just making an AR500 plate capable of passing Level III is certainly doable, but such a thin plate does not have the same level of protection as a thicker plate, thus, manufacturers came up with Level III+. Just like +P loadings of ammunition, III+ is not officially sanctioned, however it is industry recognized. Level III+ designates a plate that is designed to perform above and beyond the bare minimum of Level III, but due to the nature of the material, cannot be made capable of defeating AP rounds.
Issues also arise in the Level IV market for similar reasons. The current NIJ testing protocol allows for manufacturers to send in tons of plates so that each plate only has to endure a single round. Granted, this is a serious AP threat, but it creates a minimum that does not reward exceeding. Some manufacturers of advanced ceramic plates make plates that are capable of surviving several AP threats, but these advanced plates are still only labeled Level IV, just like their lesser counterparts. This places the burden of proof on the manufacturer to prove that their plates are capable of surviving multiple hits, and regardless of how well they perform such a test, there will always be naysayers that would be silenced by an official NIJ “Multi-hit” designation.
The most important take-away from this discussion would be just to look into what the plates you plan to purchase were designed for. Were they designed to pass a single test? Or where they designed to exceed that minimum and provide the greatest balance of practicality, performance, and cost?