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Discussion Starter #1
What kind of energy is needed to penetrate Class I, II, III, and IV body armour anyways?

SOTIC tested the M118 round against 13 layers of Kevlar (The equivalent of PASGTV vests) at 800 meters, and had 100% penetration. The tried the same thing with a 10 gauge mild steel behind it to simulate a trauma plate, but the round only had 80% success.

As such, according to "Staple" muzzle velocities of the round (Dug them off of a table, not too sure of it's quality, but it looks to be good), the round hits when it's muzzle velocity sits at 1435 fps, giving the bullet 2828 Joules of energy (Assuming it weighs 173 grains). This translates into 16.347 Joules/grain. So that covers the PASGTV vests, but what about the other vests? Granted, this info isn't too readily available (Not too many people are going to readily offer you their product's weakness), but it'd still be nice to know.

Edit;

Really fucked up that math bad. The Joules on the Federal Match Gold by 500 yards is 1250, much less 2828. Hmmm. Apparantly E = 1/2MV2 (Squared, not 2) is wrong for this. asdasdasfasds. Lousy math.
 

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Well, I wish it was purely based only on energy. In reality, it has little to do with energy. Penetration is based more on sectional density, combined with velocity/energy. I personally do not know everything involved, but I do know sectional density must be a part of the forumla. SD is a value that is based on the diameter of the bullet, the length and the grains. Longer, heavier bullets penetrate better. The 6.5 bullets have very high sectional densities for their weights, and are known to be good penetrating rounds because of such. Anyway, I think we need to look beyond just energy.

Does anyone know some fancy formula for penetration?

MEL
 

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Discussion Starter #3
Sorry about the bad math, i'll post a fix whenever I manage to figure out what the hell I did wrong (Using this we can compare sectional densities and energy to come up with a minimum penetration point with PASGTV, I hope).

A formula like that would be... insane. You would have to calculate in; The density of the armor itself, the effects of the surrounding armor, the additional support given by the angle of the armour, the heat of the armor, the heat of the round, the temperature of the air, the velocity at which the target is moving at, the on and on and on and on. There's a good reason the Class I, II, III, and IV armour are simply tested by shooting rounds at a clay torso in this armor. Sufficed to say; If there was a formula, you wouldn't to try it, or even look at it.

Also; What Class does PASGTV qualify as?
 

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Discussion Starter #4
Fixed my math. It says 896.356 Joules at 800 yards. This is done with a grain weight of 1 grain = 0.0000648 kilogram and a Foot to Meter calculation of 1 meter = 3.2808399 feet. I WAS using pounds instead of Kilos, and I was calculating that 1 meter = 3 feet (The lazy way).

Anyways, the sectional density of a 7.62mm round weighing 173 Grains is 11.36673538 grains / mm2 (Goddamit how the hell do I do that squared deal. I mean jesus. I can fix these thing like nothing, but I CAN'T FIND HOW TO MAKE THINGS SQUARED), and the energy per mm2 is 58.58300635 Joules.

Right. So to penetrate a PASGTV vest, a round needs AT LEAST (Just to be sure, and using the 173 grain round weight as a basis. But seeing as 100% of rounds penetrated the vest, it's probably lower);

A sectional density of 11.36673538 Grains / mm2
And energy of 58.58300635 Joules / mm2

And to penetrate the PASGTV vest with a Trauma plate (I used the 175 Grain round for this, seeing as the 173 grain rounds were the most likely to fail the aforementioned test), a round needs at least;

A sectional density of 11.43744909 Grains / mm2
And energy of 59.26138239 Joules / mm2

Unfortunately, this does crap all for us in terms of penetrating some of the newer armor out there. While 13 layers of kevlar is what the PASGTV vests have, we have no clue what they did with newer vests, and trauma plates.

If anyone else knows of similar penetration points, i'd like to know. It'd be nice to see what can penetrate what at what distance.
 

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!

I new it wouldn't be long until someone starts spamming. ....Time to start banning some accounts and blocking IP's.
 

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I think we should instate a no tolerance police. I was at a website awhile ago, and there was one spammer they didn't ban for a couple of months and the boards got out of control. I say we ban on site, just like this basket of hams. But thats just what I think.
 

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Ban them.
 

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Yes, there is absolutely no tolerance for spamming. He is now banned. Please folks, if there is any sign of spamming (or other unacceptable behavior) let me know asap and I will take care of it. Thanks FLEA for emailing me, it notified me sooner then I would have found it. I'm the process of setting up a few moderators that will help handle these problems also.

MEL
 

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Having just come in, the whole "Holy crap relevant ballistics calculations are spam?!" thing just sorta scared me into hiding in a foxhole. I figure you removed the spam posts.

Although, just a note from a Paranoid Canadian:

- I think the US Army wouldn't take kindly to discussion of the pentetrative qualities of various types of ammunition with regards to it's current issue protective ballistic vest. Just seems Iffy to me.

That said, couldn't you load armour-piercing ammunition - *Slams head into table* Because then you get overpenetration and no target damage other than a pencil-hole in them...

we have no clue what they did with newer vests, and trauma plates.
I think it may be bordering on illegal to get this data for the public domain, what with a shooting war on and all.

I see it mentioned that the ceramic (I'm told it's ceramic) trauma plate is simulated with a bit of steel. Is this accurate in terms of testing?
 

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Discussion Starter #14
Information has never been illegal. You can have someone's credit card number, and still be free of prosecution. You can know how, and when to shoot someone, and you're still free of prosecution. And making information illegal in this day and age is like making drinking a drop of water in a cup illegal; It's going to be consumed, wether or not you want it to, unless you take measures to insure it isn't (Take away the cup, hide it, keep it close to yourself).

And a Ceramic plate is a large part different from a steel plate. Ceramics will shatter, absorbing all the energy of the round. Steel will deform.
 

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Discussion Starter #16
Ceramics have been in lots of different armours, but I believe the first to use them were the RBA (Ranger Body Armoyr) suits. And Class armour really doesn't refer to the makeup of armour, it refers to what the armour can effectively stop without a certain amount of damage befalling the user.

For instance; Some of the new Interceptor vests can probably stop a .300 Win Mag when it hits the trauma plate, but they aren't listed as being able to stop these rounds. This is because instead of just running off wether or not the vest is penetrated, the originization that did the testing (They were a police orginization, don't recall the name though) simply grab a clay torso, and shoot rounds at it from all angles. If the clay is deformed too much, it's judged as being insufficent protection against that round.
 
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