Body Armor

[grayace 2]

I Agree with cam its definately not far away. You can imagine how fast the bullet is - its not a laser. Anybody who ever took part in a night-shooting with tracer bullets will say the same.

A bullet isnt as fast as you think ... it has a ballistic bow - which i admit, differs from weapon to weapon.

But what is interesting is the fact, that this soldier was attacked from so close range. I cant imagine the scenery down there but how can he stay infront of the vehicle without cover on a high traffic road like this? I mean also the fact there was no other soldier nearby is very critical from my point of view there was no othe soldier which was able to identify the car and repeat fire.

That looks like a shooting gallery for me....

BTW: Allah u akhbar means " God is great"

well dude Im 100% sure that this shooting was made over 100m (otherwise you could have seen the target hit/down right same moment you hear the weapon re-loads the chamber, not almost after)

and Im pretty sure that sniper was aiming in the head(lower part) and shot the shoulder(?) because of the distance, because sniper had his time, possibly his weapon was placed on somewhere to take support and improve accuracy... may be he pulled the trigger hardly (should have pressed halfway first, then pull all the way gently) so this could explain why he shot somewhere non-critical...

PS: if it was less than 100m and if I had shot somewhere non-critical, then I would shout more like GOD DAMN IT not GOD IS GREAT .... (yeah, allahuakbar means God is great, misinterpreted)

[dmakatra 1]

Could be a delay in the audio, Grayace. I mean, come on; a guerilla camera and internet hosting? It's like the worst combination you can get if you want accurate video footage. The only thing I can imagine which would be worse would be if he'd filmed it on a cell phone...

EDIT: Nope, nevermind. Just watched the video again. The camera shakes when the round is fired, hence no audio delay.

[sbsmac 0]

Quote[/b] ]It´s like you´re hit by a 2m big Sumo wrestler.

Laws of physics say that the momemtum imparted to the target equals that imparted to the shooter. Ie, being hit by a small-caliber round stopped by body-armour is no worse than the recoil from firing it.

[grayace 2]

Quote[/b] ]It´s like you´re hit by a 2m big Sumo wrestler.

Laws of physics say that the momemtum imparted to the target equals that imparted to the shooter. Ie, being hit by a small-caliber round stopped by body-armour is no worse than the recoil from firing it.

you forgot to add the amplifying effect of the barrel, just imagine firing with a very short barrel and a looong barrel...

PS: On the other hand, difference between recoil and impact can be explained as energy loaded on a small bullet (around 50g) hits a smaller area while recoil is affecting a 4.5 kg large weapon,

[grayace 2]

can tell easily but well this is my opinion, anybody can claim/suppose anything else.. like you said its a guerrilla cam, there is no numbers or any data to work on...

[sbsmac 0]

Sorry Grayace, the barrel has nothing to do with it. It cannot 'amplify' the amount of energy in the system, it simply directs it effectively along a single vector. :-) All those Hollywood films showing people flying backwards are nonsense. I don't personally have access to a gun but suggest if you doubt what I say that a simple experiment would be to shoot at a stack of sandbags of the same approximate weight as a man and see whether they go flying ;-)

*Edit* Here's a link about it... explanation]http://users.binary.net/thomcat/knock.html]explanation[/url]

[grayace 2]

Sorry Grayace, the barrel has nothing to do with it. It cannot 'amplify' the amount of energy in the system, it simply directs it effectively along a single vector. :-) All those Hollywood films showing people flying backwards are nonsense. I don't personally have access to a gun but suggest if you doubt what I say that a simple experiment would be to shoot at a stack of sandbags of the same approximate weight as a man and see whether they go flying ;-)

*Edit* Here's a link about it... explanation]http://users.binary.net/thomcat/knock.html]explanation[/url][/url]

sure they dont fly into air, but a bullet, whether JHP or FMJ, is designed to inflict damage on target with a high momentum on a small area which causes a shock/fracture on target regarding soft or hard...

weapon power is affected by barrel because gas flows through the surface very similar to a water drop, and after the explosion, the gas that cannot flow away will be pushing through the barrel, in final output, bullet will have much more energy loaded on itself than the weapon...

BTW, if you shoot into sand you will see more sand blowing into air then you see in any hollywood movies, thats right with a single bullet. just image what would a shotgun slug could do... and also take in account that those weapons(shotguns) are employed to breach doors in tactical ops.

[InqWiper 0]

Quote[/b] ]anything less than 100m is close range dude!  And that shot was definately less than 100m

The rifle used is at minimum an Ak47.

We use this video in our IED/Insurgent awareness training slideshow here at Ft. Bliss TX.  People from units all over the Army train from us, so I think our guys know what they are talking about.

And they told you it is definately less than 100m?

I think everyone agrees that a bullet does not send someone flying but when you fire a bullet it accelerates all the way through the barrel which is like what 0.5m? and when your body-armour is hit by it it will decelerate in like 1cm. There is also air-resistance that slows the bullet down before it hits its target but at shorter ranges it doesnt slow it down very much.

If you think the effect of the hit is the same as the effect of firing the gun then try glueing a bullet onto the gun on the part you normally have against your shoulder, hold the weapon with the bullet you glued on against your chest and fire the weapon. If the bullet does not penetrate you then the effect is not the same.

-edit

a bit tired but I hope I made sense

[Metal Heart 0]

Quote[/b] ]If the bullet does not penetrate you then the effect is not the same.

Obviously it doesn't, but only because a rifle has much larger mass than a bullet, therefore the bullet attached to the stock wouldn't gain anywhere near the speed the one that is fired does.

[Balschoiw 0]

Quote[/b] ]Laws of physics say that the momemtum imparted to the target equals that imparted to the shooter. Ie, being hit by a small-caliber round stopped by body-armour is no worse than the recoil from firing it.

Theory is so nice

Maybe that´s why a lot of people with body armor hit by small arms fire suffer from partially or totally collapsed lungs.

I didn´t talk of people flying through the air, but if a 2 m high Sumo slaps you on the wrist or back you´ll get the idea.

[guyguy1 0]

The standard issue body armor for the US military is the Interceptor body armor system. The vest itself is rated to stop a 9 mm round (forgot the velocity), fragmentation, and the plate insets in the front and back are capable of stopping .308 rounds (7.62 mm) travelling up to 2750 fps Link. The PASGT helmet can stop rounds and shrapnel similar to the size of a .22 round at up to 750 meters/second as well as the .44 magnum and 9mm calibers at limited speeds, although if it stopped something at 750 meters per second the user would be most likely killed. Even though it can stop fragments & bullets, the impact and shock would definitely knock you out or kill you, but will at the least knock the user down if he or she is lucky enough. Source for the ballistic ratings. In Afghanistan this helmet been capable of stopping a 7.62 mm round from an AK, but only from long distances (probably over 300/400 meters away or near the AK's effective range), and has saved lives by doing so (Not joking). Although you can take multiple hits with the body armor on (with plates), you would be badly bruised and have the wind knocked out of you, maybe killed. Nonetheless its totally possible to survive a few (2 or 3 at most) hits; occasionally being able to continue to fight, granted that you're wearing it with the plate inserts. I really Hope BI took some time to develop realistic ballistics because the one shot one kill to the chest in OFP got kinda repetitive..(even with 9 mm from it's effective range limit of 50 meters)

Grayace - The American who was shot in the video was hit in the chest where the ballistic plate was located, and "allahuakbar" means god is great. Just wanted to clear things up a little  

anyhow..GO BI!!!  

[franze 196]

I knew that video would show up in this discussion some time.

Somewhere out there, there's a couple of pictures of the guy in the video who was hit. There's a very nasty looking bruise displayed on his chest, and the ceramic plate is cracked. It saved his butt for sure, but it's not something you want to happen every day.

[Lightspeed 0]

The point of this post I think is to ensure that we dont have a one shot, one kill scenario. Its unrealistic, and there needs to be 2 to 3 shots on average to kill the guy.

My two cents...

Lighty

[Schoeler 0]

Quote[/b] ]Caliber is large, and range is danger close.

I neither can see the weapon used, nor is the range close. Close range is 10 - 15 m´s.

It was from a Dragunov sniper rifle. I remember seeing that when it happened. Modern U.S. body armor will frequently stop a 7.62 round on the plates, which are now ceramic and not steel by the way. That guy got up and returned fire afterwards, so the newer body armor is a whole generation removed from the stuff used just five or six years ago.

[guyguy1 0]

The point of this post I think is to ensure that we dont have a one shot, one kill scenario.  Its unrealistic, and there needs to be 2 to 3 shots on average to kill the guy.

My two cents...

Lighty

Exactly  . Any modern army with a powerful military force definitely has enough money to purchase protective vests for their soldiers. 2 or 3 shots to kill a man on average is a little unrealstic from average engagement range (100 meters or so?), I suppose. It all depends on the how far the bullet comes from. The bullet will have to hit the protective plate every single time in order for someone to survive multiple hits to the torso (hope BI did some accurate damage boxes for the models). The new ballistic plates provided by the army for soldiers in Iraq can withstand 12 shots from 5.56 mm rounds and 4 or 5 from 7.62 mm rounds before becoming rendered useless, however the user should be badly bruised/knocked out of action after 2, 3, or possibly more, depending on the range at which the bullet was fired from (Hope BI took into accurate ballistics into consideration..this is really important IMO beacuse the helmets can protect against bullets too...if fired from far enough). I'd like to see a soldier survive multiple hits because of body armor, but not too many so that the game turns into a Half Life 2. Here's a specification for the performance of model AA4 plates fielded by the US army currently.

7.62 × 54mm lead core ball ammunition, Dragunov Sniper Rifle at 0 meters

7.62 × 54mm AP, Dragunov Sniper Rifle at 0 meters

7.62 × 51mm NATO ball ammunition at 0 meters

7.62 × 51mm AP M-61 at 0 meters

7.62 × 51mm Swiss Munitions AP (WC Core) at 0 meters

7.62 × 39mm mild steel core, AK-47 at 0 meters

7.62 × 63mm AP at 0 meters

5.56 × 45mm SS109/M855 at 0 meters

5.56 × 45mm M193 ball at 0 meters

5.45 × 39mm Russian ball at 0 meters

12 gauge slug at 0 meters

almost guaranteed stoppage since these rounds can be defeated at point blank range

[max power 21]

Okay... Yes, the bullets have energy equal to the energy of the rifle that fired it. People fall down after being shot for psychological reasons or for physiological reasons (ie. leg shattered), not because it knocks them off of their feet.

This is a good paper to read on some of the basic priniciple. It is for handguns only, as it was the fbi testing for the factors of an optimum pistol load for their agents, but rifles only majorly differ in their temporary cavity profiles.

http://www.firearmstactical.com/hwfe.htm

Most military rounds actually have a problem imparting their energy to their target when they penetrate bare flesh, so the *impact* of the round stopped by body armour would actually feel more violent than if it passed through, since more energy is delivered in a shorter span of time.

The actual 'equation' for energy is KE = 1/2 * m * v^2

where KE is kinetic energy.

where m is mass and v is velocity.

where velocity is also distance/time.

The rifle/bullet accellerating away from the bullet/rifle do so for the entire length of the barrel. In order not to penetrate a man, the bullet must decellerate INSTANTLY. You can imagine the problems with this... it is one of the problems that body armour has tried to solve.

Another is the reason why bullets penetrate. Their energy is delivered over a much smaller area than the butt of the rifle. You can bet that if the butt of the rifle was shaped like a bullet, it would probably stab you - especially if the rifle had no muzzle brake. I challenge one of you to try this. Don't use a live round in between the butt of the rifle and your shoulder, though, I don't want you triggering the percussion cap and confounding our little experiment. Body armour takes that energy and resists tearing, and thereby spreads the energy of the bullet out over the entire plate. If the plate is ceramic, is also absorbs energy by shattering.

And, after all is said and done, a man may take lots of hits before he dies. He may take a hit and die a day and a half later... I bet that many of the injuries suffered in ofp are crippling/deadly injuries.. you just get to survive because your life is only as long as the map. That said, if you get hit 4 times in the torso (something that would kill you in ofp), and none of those hits hit your heart or major arteries, you might have quite a while of useful conciousness left... who wants to spend that time as a paraplegic, though, in the case of a spinal injury? It's not so much shot power as shot placement. Instant kills would happen only in the cases of a hit to the CNS, and quick kills would happen in the case of major blood loss. The rest is a long haul to the hospital and/or, eventually, the morgue.

[grayace 2]

well Im going to claim it once more, its either my stupidness (Im not a physics expert) or some physics guy that is calculating the case incorrectly.

(IMO) Recoil is definately NOT reflecting equal amount of energy to the bullet's

I fired with M1 Garand (which is still in use as M14,M21,M24 with modifications) and its recoil was "nothing" just like a somebody punching you in joking manner, but its effect is definately far different on target. and weapon weight is around 3kg!

I also fired with HK G3, damn good rifle but it has a very bad recoil, its more like somebody kicking the barrel enough to distrupt your aiming and weapon weight it 4.5kg!

*both rifles are using same caliber/round

Now I wonder how come that a heavier weapon could result with more recoil. Here is the answer (IMO) you forgot to add combustion of gas during the explosion

and also possible solution to that M1/G3 thing is, during the shot some of the gas was escaping through the loading hole because it is very large, enough to fit full cartridge while in G3 its smaller, designed to use discard the empty cartridge and with a delay to reduce the gas loss.

And also for bolt action sniper rifles are desinged to use all the gas in the chamber by sacrifiying semi-automatic loading...

-For Allah u akhbar thing, I already corrected my fault, and I also I would more like say god damn in that case...

[max power 21]

Trust me. Unless you take physics, you will have to trust me and the others on this forum, and a thousand years of physicists, that the energy of the bullet is the same as the energy of the rifle.

You should conduct our experiment. Take a pair of pliers and pry the bullet out of the shell casing of a 7.62 round, remove any muzzle brake on the m1... place the bullet between your shoulder and the buttstock.. let the rifle float freely in your open hands, and get a friend to touch the trigger with a piece of dowel or something.. see what happens

What is the stock of your m14 made of compared to the stock of teh g3? How do the muzzle brakes compare? How heavy/long is the action of the g3 compared to the m1? And I'm not sure of the m1 fires the same round as the g3.. you would know if it has been converted or what... this would be another factor.

And I don't think I neglected to take into account the expansion of gasses. This doesn't make much sense. The gasses push back on the rifle as hard as they push forwards on the bullet, and they push up on the top surface of the chamber as hard as they push downwards, etc.

[grayace 2]

Trust me. Unless you take physics, you will have to trust me and the others on this forum, and a thousand years of physicists, that the energy of the bullet is the same as the energy of the rifle.

You should conduct our experiment. Take a pair of pliers and pry the bullet out of the shell casing of a 7.62 round, remove any muzzle brake on the m1... place the bullet between your shoulder and the buttstock.. let the rifle float freely in your open hands, and get a friend to touch the trigger with a piece of dowel or something.. see what happens

What is the stock of your m14 made of compared to the stock of teh g3? How do the muzzle brakes compare? How heavy/long is the action of the g3 compared to the m1? And I'm not sure of the m1 fires the same round as the g3.. you would know if it has been converted or what... this would be another factor.

And I don't think I neglected to take into account the expansion of gasses. This doesn't make much sense. The gasses push back on the rifle as hard as they push forwards on the bullet, and they push up on the top surface of the chamber as hard as they push downwards, etc.

well you trust me either, we are not firing in space and "the gas" well it really *matters*

both M1 and G3 are using same NATO round 7.62x51mm, sorry I inserted this info later in edit.

well as far as I know, if I was firing in water or in space your suggestion would be perfectly true and the barrel will be only used as aiming purposes. But in a gas filled environment it is totally different. gases are *amplifiying* the energy on the bullet, during post-explosion gases blow to directions other than the barrel exit will reflect back and create a combustion which will increase the energy on bullet.

just base on those bolt-action sniper rifles, why would they use such an old system then?

like I said, Im not physics expert and I cannot discuss this in advanced calculation with you, Im just telling my opinion which is based on some deductive logic...

[Metal Heart 0]

Newton's 3rd law: "For every action, there is an equal and opposite reaction." The bullet & gun scenario is often used as an example of this law.

It only seems that the bullet has more energy than the gun because it's something like 400 times smaller in mass. The same force that is accelerating the bullet out from the barrel is also accelerating the gun in the opposite direction.

I'm quite sure that the atmospheric pressure doesn't have a significant effect to the forces caused by the explosion inside the barrel. I'm not going to pretend that I understood anything about your gas reflection and amplification theories though

[Balschoiw 0]

Ok let´s get this back into context.

Body armor is nice. But the ones who think that you´ll get hit by 7.62 or even 9mm and just stand up and fight on are a bit off imo.

You will not be able to fight on. You will for instance experience an adrenalin thrill that will keep you actived and on high alert for a while but afterwards you will suffer from a lot of possible and likely injuries and traumatas that will render you useless.

As ArAs will be a game with at least 2 opposing sides, that need to be balanced to some extent I´m not sure if the body armor concept should have that much weight for reasons of playability.

A side benefit would be created that would make 2 sides MP battles rather useless as one side would share a major benefit. I don´t know if this would be that much contrbuting to the overall gameplay experience for all participating sides. In the end it´s still a game with a balanced concept.

Apart from that the Interceptor body armor has had some serious flaws and test procedures showed that some lots even can´t withstand 9mm shots. So if you really wanted to simulate body armor correctly you needed to include a fail option as there is a risk that body armor will not work properly due to material failures or simply wrong handling of the body armor and it´s components.

For a brief read on body armor failure read this:

Defence contract management memo

Memo from US army

Photograph of test failure

For sure the body armor currently used is a benefit for the soldier who wears it but keep in mind that IRL the ballistic effect is still there and noone will just stand up after a bullet hit and just fight on as if nothing has happened. That´s nonsense.

[EiZei 0]

http://www.nytimes.com/2006....f=login (account mattedialog/asdfghjk works at the time of writing)

According to a recent secret pentagon study more than 80% of marines that died of upper body wounds might have survived it with proper body armor. Of course this does'nt mean they could have kept on going but still..

As an another example, the robbers in the north hollywood shootout were wearing kevlar (practically covered in it) and kept on going despite both robbers being hit over ten times with pistol rounds fired by the officers on scene. On the other hand, they barely hit anything and were probably high on something.

[Gollum1 0]

What do you think about this article with included video, Bals? Maybe it was just a really long adrenaline rush and he collapsed, "useless", afterwards?

Note that the 7.62x54R round he was hit with is quite a bit more substantial than an AK round. I read in Time magazine about Operation Anaconda, the reporter mentioned a U.S soldier being hit with 2 7.62x39 bullets in the chest and immediately springing back up and rejoining the fight. Accounts like this surface regularly.

I think the 6000 or so flawed Interceptors that the USMC recalled make up about 3% of the fielded Interceptors in Iraq.

edit: Damn, didn't read the thread, posted on the last page Sorry, well my point still stands.

[Gollum1 0]

http://www.nytimes.com/2006....f=login

According to a recent secret pentagon study more than 80% of marines that died of upper body wounds might have survived it with proper body armor. Of course this does'nt mean they could have kept on going but still..

Yeah, and if they would be enclosed in cubes of Cobham armor the casualties might be reduced even more. There are already complaints that U.S infantrymen's armor ("happy gear") is too hot and heavy. Hell getting many to wear the plates was a pain in the ass until they started enforcing it.

You have to strike a balance between protection and combat effectiveness. Extra armor reduces your effectiveness in combat by reducing your mobility, endurance, reaction time etc. and that is just as likely to cause your death as anything.

Extra armor for convoy duty is another issue.

edit: not saying that the existing vests can't be improved, but saying that "troops died because of too little armor!" is as clear as saying that people need water and food to survive. A less sensationalist approach in that article would be to say that the military has recognized flaws in the vests and are now working to correct them. It isn't some big scandal. Hell, if this war has ANY success story, it is in terms of the individual body armor the troops have. An honest headline on this subject would be MILITARY INVESTIGATES IMPROVEMENTS TO ARMOR THAT HAS SAVED THOUSANDS OF LIVES IN IRAQ.

[Cam51 0]

What do you think about this article with included video, Bals? Maybe it was just a really long adrenaline rush and he collapsed, "useless", afterwards?

Note that the 7.62x54R round he was hit with is quite a bit more substantial than an AK round. I read in Time magazine about Operation Anaconda, the reporter mentioned a U.S soldier being hit with 2 7.62x39 bullets in the chest and immediately springing back up and rejoining the fight. Accounts like this surface regularly.

I think the 6000 or so flawed Interceptors that the USMC recalled make up about 3% of the fielded Interceptors in Iraq.

The article said 75 yards away.  LMAO. Hate to say it, but dam if feels good to be so right.

Saying a soldier would be useless after taking a hit in the armor is pretty narrow minded.

But I agree for ArmA there needs to be a feature that knocks you down when you get hit, but depending on where you got hit will depend on how effective you are afterwards (ie: hit in the arm = LARGE drop in rifle steadiness)