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Not actually Erin.
& is used with permission.
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Erin, why do you call it "ballistic armor" when everyone else calls it "body armor"?
What you need to understand is that "body armor" is a legal term which, according to 18 USC § 921(a)(35), states The term “body armor” means any product sold or offered for sale, in interstate or foreign commerce, as personal protective body covering intended to protect against gunfire, regardless of whether the product is to be worn alone or is sold as a complement to another product or garment.
The problem with legal terms is that they are often semantically incorrect, which is why laws go to pains to define them. As an example, the legal definition of a "machine gun" works out to mean "anything that fires more than once with a single pull of the trigger". This is of course garbage terminology, as this would mean any select-fire M4 carbine used by the US military is a "machine gun", and yet that same US military -- who ought to know the proper definitions, as they actually buy, use, and fight with them -- defines a machine gun as a weapon that fires small arms ammunition, caliber .60 or 15.24 millimeters or under, automatically and is capable of sustained rapid fire. The salient point here is "sustained rapid fire"; good luck sustaining any rapid fire through a magazine! No, they need to be belt- or link-fed for that. The lightest machine gun in the US arsenal today is the M249 LMG, which looks and acts completely differently from the M4 carbine.
Similarly, "body armor" is anything which protects your body from protection. Yes, ballistic plates are body armor, but so are riding leathers which protect your body against road rash if you fall off your motorcycle, as is the hard plastic shell called a "riot control suit" that police use to protect against blades and blunt trauma. Neither of these things will protect against a bullet, but ballistic plates will (it's in their name!) and so I make the differentiation between ballistic armor and other types of armor.
Levels of Protection
If you want Protection and Mobility at the cost of Quality, you end up paying too much for "protection" that won't protect you, usually because they skirt the rigorous NIJ (National Institute of Justice) certification. Don't ever do this.
If you want Protection and Quality, you will lose Mobility. The armor will be difficult to move and shoot in, and so heavy that it will fatigue you quickly.
If you want Mobility and Quality, then you sacrifice Protection. This sounds like a terrible idea but it's not as bad as you think, and this is because there are different NIJ levels of protection which give us a sliding scale between Protection and Mobility. To reverse the statement in the previous paragraph, if you lighten the armor to regain Mobility you lose Protection.
The trick is finding your personal "sweet spot" of Protection and Mobility at a Quality you can afford, and you do that picking your level. Ballistic armor comes in five levels: IIa, II, IIIa, III, and IV. (Level I armor is no longer made.*) As the numbers increase so does the protection they give, but you pay for that with weight and with cost. Somewhat counter-intuitively, IIa and IIIa are actually a step below levels II and III respectively, and I have no idea why.
There are a few points I want to make before I continue:
- The following data comes from the most recent NIJ certification PDF. Go there if you want more information.
- Each panel or plate is shot 6 times in different locations. In real life, multiple hits in the same location are possible and may produce a higher failure rate.
- Some tests (see below) are performed with non-expanding full metal jacket (FMJ) ammunition, which is more likely to penetrate armor than the expanding jacketed hollow point (JHP) ammunition found in most pistols in the US.
- Armor levels IIa, II, and IIIa are shot using handguns. There is no NIJ data for handgun rounds shot from carbine or rifle-length barrels.
- The physiological effects of being shot while wearing ballistic armor are a subject for another blog post.
Level IIa Armor
Made from ballistic fibers, this lightweight (less than 10 pounds) soft armor has largely fallen out of favor due to the fact that advances in materials science has made higher levels of protection more cost-effective. The only people likely to still use IIa armor are undercover agents who need protection that is difficult to detect. It is rated to withstand up to 6 shots of 180 gr .40 S&W FMJ without penetration at a distance of 5 meters (16.4 feet).
Level II Armor
Thicker and heavier than IIa armor but still soft and very flexible, level II armor is somewhat comfortable, at least in comparison to heavier armors.
It is rated to withstand up to 6 shots of 158 gr .357 Magnum JSP (jacketed soft point), not FMJ without penetration at a distance of 5 meters (16.4 feet).
Level IIIa Armor
This is usually soft armor, although some IIIa plates (known as "speed plates") do exist. It is of course heavier, bulkier, and more expensive than previous levels, although it is still somewhat flexible (plates notwithstanding).
It is rated to withstand up to 6 shots of 240 gr .44 Magnum SJHP (semi jacketed hollow point) without penetration at a distance of 5 meters (16.4 feet).
Level III Armor
No longer soft, this armor and above are known as rifle plates because they are rigid plates of steel or polyethylene and are rated to withstand rifle shots. They are heavy, bulky, tiring to wear, and the good ones are expensive unless you can get a screaming deal on them.
Level III armor is rated to withstand up to 6 shots of 147 gr 7.62 NATO M80 FMJ without penetration at a distance of 15 meters (49.2 feet).
As a point of interest, the velocity of this round is 2780 fps, whereas the .44 Magnum in the previous test only achieved 1340 fps and the velocity of a 300 gr .50 Action Express is 1550 fps. In other words, level III armor ought to protect against anything shot from a pistol.
Some armors bill themselves as "Level III+" but there is no NIJ certification for such a level. This is because some types of 5.56mm ammunition can penetrate regular level III armor, like M855 “Green Tip" versus polyethylene plates or M193 against AR500 steel armor. Level III+ claims to protect against both M855 and M193, but there is no way of certifying such a claim and unscrupulous sorts might make the claim in order to convince you to pay more for a level III plate. If this is your concern, I would suggest you look at level IV plates instead.
Level IV Armor
These plates are made from either ceramic or metal. The difference between ceramic and metal plates is the subject for a later blog post, but the short version is that metal plates last longer and withstand more shots but feel much heavier and there is risk of injury from spalling, whereas ceramic plates have a shorter lifespan and frequently cannot withstand more than one hit, but are more comfortable to wear and there is no risk of spalling.
Level IV steel armor is rated to withstand up to 6 shots of 166 gr .30 M2 AP (armor piercing) without penetration at a distance of 15 meters (49.2 feet).
Level IV ceramic armor has the same rating up only up to 1 shot.
Level IV steel plates are everything I said about level III and then some. I have worn level III steel and within 5 minutes my shoulders hurt; after 15 minutes I was in such discomfort that the only thing which would make me keep them on is being shot at.
I also own level IV ceramic armor. While it weighs about the same as level III steel, because it is larger it feels lighter due to the larger dispersion of weight. I was able to wear my level IV for 15 minutes before feeling a stiffness in my neck and shoulders (that "I need to stretch it and make it go pop" feeling) but I was able to wear it for an hour before I started to cramp up.
There is no such thing as level IVa armor.
* For the curious, I discovered that Level I armor is rated up to 5 hits of 158 gr .38 Special ammunition. https://www.ncjrs.gov/pdffiles1/nij/099859.pdf
Next week: Materials
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