http://www.lightfighter.net/topic/le...rol-armor-test
Uniformed LE officers typically wear concealable soft armor, typically Level II or IIIa, on a daily basis. However, in high risk situations, including Tactical and Special Operations, active shooter incidents, and violent felony warrant service there is a significant risk of injury from common center fire rifle threats that can easily defeat concealable soft armor, irrespective of whether the rifles are chambered in traditional civilian hunting or military calibers (ex. 5.56 mm, 6.5 mm, .270, .30 carbine, 7.62x39 mm, .30-30, .308, 7.62x54 mm, .30-06, .300 Win Mag, .45-70). In these situations, it is imperative that law enforcement officers have Level III or IV hard armor plates to protect against rifle caliber threats.
Some LE agencies have been guilty of only purchasing front plates for officers in order to save costs, however, only providing rifle protection to the officer’s front is asinine, as has been demonstrated in many tragic fatalities when rifle shots have come from unexpected directions other than the front. Officers MUST have both front and rear plates. For those officers routinely involved in high risk missions, additional side armor plates might also be appropriate.
For SWAT and other Special Operations use, purchasing dedicated tactical armor carriers without hard armor rifle protection is ludicrous.
When looking at hard body armor, LE Agencies need to assess what threats they anticipate in their area of operations, local geography, environmental concerns, as well as mobility needs.
For OCONUS military and para-military settings, level IV plates capable of stopping AP rounds may be a critical requirement. In some settings, the most important rounds to stop are 7.62x39 mm steel core M43 FMJ and 7.62x54 mm Type-L FMJ; in other areas, the ability to stop AP rounds in those calibers is also crucial.
For the typical LE officer within CONUS, it is highly unusual to be confronted by opponents using AP ammo; it is much more likely to be hit with FMJ and expanding hunting rounds from rifles in calibers from .223 to .30-06, as well as 12 ga. shotguns. In addition, LE agencies need to ensure their armor provides protection against all issued duty and training ammo.
Thus for CONUS LE use, multi-hit capable Level III plates capable of stopping 5.56 mm M193 and M855 are a good choice.
For uniformed LE officers already wearing concealed soft armor, a simple hard armor plate carrier without cummerbund, like those available from many vendors, is the most cost effective and simplest way to add Level III or IV armor protection. In addition, in an active shooter incident, a simple plate carrier is the most rapid type of hard armor for officers to don that offers protection from rifle threats. Simple hard armor plate carriers with Level III multi-hit 5.56 mm tested plates are perfect for uniformed patrol officers and should ideally be available in every patrol car in America. For a planned event that offers some preparation time like a high risk warrant service or Tactical/Special Operations assignment, dedicated tactical armor worn with Level IIIa soft armor inserts and appropriate Level III or IV hard armor plates are quite common, however, these take a fair amount of time to don and cannot be worn by uniformed personnel already wearing concealed soft armor. Thus, these are not ideal or effective for uniformed patrol personnel. Low profile hard armor carriers look similar to normal soft armor carriers, but are designed to carry not only the soft armor, but also hard armor plates. These are great for many high threat situations, especially during extended field use, vehicle operations, or in environments where hard armor needs to be concealed with a large jacket or other outer garment. Low profile hard armor carriers can be worn alone or are often combined with low profile chest rigs. These systems allow protection from rifle fire and a much reduced kit signature with good mobility and easy access into/egress from vehicles. In high threat areas, they can be worn instead of typical soft armor carriers.
Keep in mind that the NIJ Level III test only uses 6 hits of 7.62 x 51 mm M80 FMJ. The NIJ Level III test does NOT use ANY 5.56 mm threats. While some Level III plates may stop 55 gr FMJ M193, 62 gr FMJ M855 “green tip”, and other 5.56 mm loads, other Level III plates may not. LE agencies must be sure to get the specific threat caliber and exact ammunition loads and velocities that Level III hard plates have been tested against in WRITING from the armor vendor, as the NIJ Level III rating does NOT certify hard armor plates against ANY 5.56 mm threats. Likewise, the NIJ Level IV test only uses from 1 to 6 hits of WWII era .30-06 M2 Black Tip AP. It does NOT assess armor capability against ANY modern AP threats like 5.56 mm M995 and 7.62 x 51 mm M993. Nor does it test against any Level III threats. Again, LE agencies must ensure they get the specific threat caliber and exact ammunition loads and velocities that Level IV hard plates have been tested against in WRITING from the armor vendor, as the NIJ Level IV rating does NOT certify hard armor plates against ANY modern AP threats.
Currently there are four common options for Level III plates:
5-6 mm steel (AR500/R50c/AR46100) plates: Level III steel plates offer a very thin profile, but are a bit heavier (6.5-7.5 lbs for a 10x12 plate) than some other options. They are very durable and offer inexpensive multi-hit capability against even closely spaced non-AP 7.62 x 39 mm and 7.62 x 51 mm projectiles, as well as for heavier 5.56 mm loads, including 62 gr M855 “green-tip”. Unfortunately, many lightweight (55 gr or less) 5.56 mm loads will defeat steel plates, including the extremely common 55 gr FMJ loads like M193. It is a VERY good idea to wear level IIIa soft armor underneath steel plates. These are likely NOT a good option for CONUS LE officers.
Hard compressed polyethelene (Dyneema/Spectra) plates: These are very lightweight (3-4 lbs for a 10 x 12 plate) multi- hit capable level III plates that will stop closely spaced hits of both the lightweight 5.56 mm ammo that defeats steel, along with the 7.62 mm threats stopped by steel, as well expanding rifle ammunition in many hunting calibers. Unfortunately, hard polyethelene plates are often perforated by current military issue 5.56 mm 62 gr M855 FMJ “green-tip” and 5.56 mm M855A1 62 gr ammunition. While not necessarily required, it is not a bad idea for compressed polyethelene plates to be worn in conjunction with soft level IIIa armor underneath. These are NOT an ideal option for CONUS LE use.
Non-ceramic hybrid plates: These combine several non-ceramic materials, for example both steel and hard polyethelene layers, and appear to offer the most robust protection of any current level III plates. They are very durable and stop multiple closely spaced hits of almost all non-AP ammo, including high velocity 5.56 mm threats, as well as M855; however they are typically a bit heavier (7-7.5 lbs for a 10 x 12 plate) than some other types of hard armor. These are typically NIJ stand- alone capable, so soft armor is usually not required underneath. These plates typically are quite durable and generally do not require annual non-destructive testing.
Ceramic plates: These plates are relatively lightweight (4-6 lbs for a 10 x 12 plate) for the protection provided, but can be more susceptible to occult damage in day-to-day use, and usually cannot withstand as many closely spaced hits as other plate types. Ceramic plates should ideally undergo non-destructive testing (x-ray, ultrasound, etc...) each year to ensure that hidden cracks are not present. Ceramic plates are available in both in-conjunction and stand-alone configurations. Note that almost all level IV plates use ceramic elements in order to stop AP rounds.
Ceramic hybrid plates: Most ceramic hybrid plates combine ceramic materials like silicone carbide, aluminum oxide, or boron carbide along with various other materials, including metal, compressed polyethelene, etc... These plates are often heavier than pure ceramic plates, but are a bit more robust, with potentially better multi-hit protection and greater durability. Nonetheless, periodic non-destructive analysis is recommended because of the ceramic elements. Ceramic hybrid designs are often used in stand-alone level IV plates intended to stop AP projectiles.