Beefing up body armor?

[Messenger Guard]

In my line of work body armor is not mandated but heavily advised. Most wear Level II, II-A, or III. Some fellows have taken to "hillbilly beefing" their armor in critical areas. Some examples I have seen are stacking two soft trauma plates over the heart, sliding in aluminum plate in the back, adding electrical tape covered aluminum plate over the soft trauma plate. The rational has been the aluminum is light and deflects knife attacks. The fellow with the aluminum plate over his soft trauma plate says he read N.Y. City Police had used steel plates at one time but had ricochets from small calibers bounce up through their chins hence aluminum would allow the bullet to pass but break up. None of these guys are ballistics experts. My interest is would the aluminum plate being hit actually cause the vest to fail? I'm thinking the vest will be cut into by the shards of aluminum once the bullet clears the plate thus weakening the vests ability too bring it's entire collective strength to keep the bullet from passing into the man. I'm thinking if this was a good idea most vest makers would install aluminum plate over the soft trauma plates.

 

[hso]

aluminum would allow the bullet to pass but break up.

Not possible.

aluminum plate being hit actually cause the vest to fail?

Probably not

Vest makers use ceramic composites because of the performance and minimized thickness.

NO manufacturer puts Al plate over soft armor and none, that I'm aware of, put it under.

 

[Double Naught Spy]

JBIT makes aluminum inserts. As of a few months ago, they were undergoing NIJ testing.
http://www.freerepublic.com/focus/f-chat/2525358/posts

Here is some future aluminum prospects...

http://www.bodyarmornews.com/body-armor-news/aluminum-nanometal-is-strong-as-steel.htm

 

[Rusty Shackleford]

If I remember correctly, I was told by a buddy of mine who used to be in the body armor business that if you put something inflexible behind the vest, bullets can go right through. It seems that your body actually absorbs a good amount (if not most?) of the bullet's energy. So if you were to put the vest on a tree or something, you'd get a pass through even of a round the vest was rated for. He said that's why they have to use special clay or gel when testing them.

I would imagine this would apply if you were going to put some kind of hard plate behind the vest too... Just FYI, you might want to make sure your buddies put any kind of hard plate on the OUTSIDE of the vest and not between them and the vest.

 

[Double Naught Spy]

That sounds about right. As the body flexes inward from the impact, it allows the vest more time to "catch" the bullet. Plus, something hard behind the vest means that the incoming bullet can crush the fibers against an anvil-like surface.

With that said, some of the steel inserts are wrapped in layers of kevlar. The kevlar isn't to stop the bullet from penetrating. That is what the steel does. The purpose of the kevlar is to help trap the spall or splatter of the bullet after it hits the plate and hence preventing the spall or splatter from impacting those parts of the wearer's body that are forward of the vest such as the chin/face, arms, etc.

Many thicker ceramic plates capture the spall/splatter by letting the bullet partially penetrate and the pieces are then trapped within the plate.

 

[Trent]

You've got several hundred foot pounds of force with a very small cross-section impacting you. Do you really want a piece of aluminum deforming in to your chest?

The point with ceramics is they crush with a minimal of "splatter", and are usually wrapped with kevlar to prevent the escape of secondary projectiles. Rifle rounds which are defeated by metal tend to splatter with great energy. SAPI plates contain several layers of different material (can't recall the composition off the top of my head), but the purpose of the design is to force the slowing and deformation of a rifle projectile prior to it getting to your body.

Adding extra plates - aluminum, steel, or otherwise, will not protect you from rifle rounds one bit, unless those plates are proven to defeat the projectile standalone. It is not safe to assume that it will protect you any better against handgun rounds higher than the vest is already rated for.

Vests are shot with a clay backing so they can measure the amount of deformation. In order to be certified to NIJ standards, vests have to defeat projectiles while not exceeding a certain MAXIMUM amount of clay deformation behind it. This represents and indicates the amount of blunt force trauma sent in to your body. Vests which allow too much energy to be transferred over too small of an area will not receive certification to NIJ standards, as those vests could allow potentially lethal force to enter the body, even though the projectile itself is stopped.

On the matter of putting in steel plates; I've shot a lot at and through steel plates, including 223, 308, 7.62x54R, 7x57 mauser, 8x57 mauser, 7.5 swiss, 300 Win Mag, and 50 BMG over the years. 308 FMJ will readily penetrate 3/8" mild steel, while harder steel might stop it in it's tracks. Most stuff you get your hands on, that you could reasonably fit in to a trauma pouch, will not readily defeat a rifle round. Even if it does, I wouldn't want my face anywhere CLOSE to the plate if a rifle round hits it.

There are very few plates certified to stop repeated hits by 7.62 NATO / 308, but there are some on the commercial market beside the SAPI plates used by the military.

If you are in a line of work where bad guys with guns are a possibility, and you are concerned about the possibility of small arms fire, why take chances with some bit of scrap metal and duct tape from the hardware store when there are items perfectly suited to the task and readily available commercially?

NOTE: This link is to a 1.2 MB PDF document identifying NIJ test standards for certification.

NIJ Body Armor Certification Guidelines

This is a link to a listing of all currently certified makes and models of body armor which have been tested and found to be compliant. (Be patient, takes a minute for the list to appear.)

Ballistic CPL Listing

 

[Double Naught Spy]

You've got several hundred foot pounds of force with a very small cross-section impacting you. Do you really want a piece of aluminum deforming in to your chest?

That is exactly what happens with Kevlar, so I am not sure of your point. A IIIa soft armor vest will stop a .44 mag with over 1200 ft lbs. and the wearer will survive.

One of the benefits of the aluminum is that the impact would be spread out over a much larger area and press inward less.

JBIT's aluminum armor have passed NIJ tests, so that amount of deformation that you are concerned about is within the parameters of the NIJ. They don't exceed it.

Here is JBIT's website. They don't have listed the levels of the plates, only that some are rifle plates. And it would appear that the plates are wrapped in kevlar as well.

See footage here...
http://jbitusa.take2pro.net/#

I liked the first vid showing the plate absorbing a lot of rounds. They claimed 60, but given the number of edge shots shown, I am thinking at least a few rounds fired by the officer failed to hit the plate.

The plates, like ceramic plates, appear to absorb and trap the incoming bullet and most of its parts.

Technology is changing. The large rifle plates (ceramic) I got nearly 10 years ago weigh in excess of 22 lbs each. Imagine getting comparable protection with plates weighing no more than 5 lbs each.