Originally Posted by shillard
Completely incorrect.
A "trauma shield" is SOFT material sitting under the kevlar layers of, for example, the IIIA "interceptor" body armour worn by US service personnel.
The kevlar will stop pretty much anything coming out of a shotgun, pistol, sub-machine gun, etc as well as fragments from bombs/ grenades/ mortar rounds. etc. The Kevlar physically entraps the projectile, but does not stop the kinetic energy, which can cause "blunt trauma" injuries to the vest wearer.
The SOFT trauma shield is designed to absorb/ spread that kinetic energy, and thus prevent a stopped bullet bursting your liver or causing your intestines to bleed out.
The HARD PLATES in modern body armour provide increased protection from high-velocity projectiles (typically rifle and machine gun rounds). They do diddly-squat to stop trauma, and wearing a hard plate without a trauma shield can lead to a burst liver or bleeding intestines....
Eg: The US-issue "interceptor" vest won't stop a round from an AK-47 without the plates (well, it might at long range, if you're REALLY lucky), but with the hard-armour plates will allow you to take half a dozen rounds from an AK-47 in the chest at close range, then get back on your feet and shoot the stunned mullet who shot you.
The so-called "cermic" plates in the interceptor vest are actually made of boron-carbide, with a spectrashield backing. They WILL activate most metal detectors.
A soft kevlar vest, complete with SOFT trauma shield, will not.
I used to think the flak vests issued to us were just that: great for protecting us against fragments from an explosive device, landmine, etc but not very effective against small arms fire. Then I saw a video clip of a soldier in Iraq who was shot by a sniper. The soldier went down, moved a little bit and then stood right back up with his weapon at the ready looking for the sniper. Unfortunately, not much information was available, but I think it's safe to assume that the sniper probably used an AK-47 and that the range was within 100 meters (most combatants lose accuracy due to panic, excitement, fear and other combat factors). Could be wrong, but like I said, there wasn't much supplementary information with the video clip. It was enough to dispel my previous beliefs about the flak vests.