In fiction, a bullet-proof vest is pretty much bullet-proof; you end up on the floor with a hole through your clothes, but the vest stops (and usually flattens) the bullet, and apart from bruising, you’re OK. This works against basically every weapon that isn’t specifically called “armour piercing”, which on the other hand goes straight through.
How good are they in real life? I’m assuming there’s a spectrum from low-level vests to whatever the hightech body armour standard is these days, but can you take a shot to the chest from a big honking handgun and not suffer from it? Shotgun? High-powered rifle? How much does range matter? How much does it help against explosives and shrapnel?
Since the biggest danger of being near an explosive detonation is damage due to the compression of air in the lungs and ears, any type of suit would be insufficient for proper protection. Distance is the best way to mitigate blast overpressure, as pressure atrophies logarithmically with respect to distance. Shielding (barriers including sandbags and concrete walls) are much more efficient than any type of suit for being able to contain shrapnel and attenuate the percussion wave.
Getting hit by a bullet in a typical vest still feels like someone came up and gave you a good whack with a hammer and you will have some wicked bruising. The nice part is, you walk away with your blood volume still inside.
Because you still absorb all the energy it is not unknown for people to die from blunt trauma injuries suffered from the impacts. No cite but there was a news piece I saw a long time ago involving a point blank shotgun hit to a vest that shattered a couple ribs and badly lacerated the officers lung, he did not survive despite his intact vest.
Huh? If the explosive detonation in question is a gun being fired, and you’re in the path of the bullet, it seems to me that you’re facing bigger dangers than air compression. And that a bullet-proof vest ought to provide some protection against those dangers.
The last question in the OP was “How much does it help against explosives and shrapnel?” I’m assuming Santo Rugger’s post was in reply to that question only.
Guns loaded with smokeless powder don’t propel the bullet through explosive detonation. Nitrocellulose/nitroglycerin based propellants burn rapidly and produce large amounts of gas which propel the bullet. They don’t explode.
That’s not entirely true. Bomb squads have access to special suits which will protect them from some explosions. It’s not something you would use in a gunfight (big bulky suit, massive helmet, etc) but I’ve seen demonstrations involving a guy immediately adjacent to a pipe bomb detonation and the subject was fine.
Good links already posted, but in brief: good quality modern body armor should stop most handgun bullets. That include most bullets fired from machine pistols (like uzi or mp5). They won’t stop rifle bullets. Most concealable armors are of that level.
Standard caliber rifle bullets should be stopped by armor plates (that usually take form of inserts into bullet-proof vest), but armor plates are heavier, more rigid and hence covers only part of the body (usually chest and back). Military or SWAT vests, worn on the outside are usually equipped with such plates.
High caliber rifle bullets (.338, .408 or .50) probably won’t be stopped by any reasonable body armors.
Shotgun slugs are approximately as good as standard rifle bullets in penetrating vests. Buckshot is similar to several shots from handgun, but concentration of lead in one place and time makes it more effective - even if penetration would be stopped, there is a chance of causing serious internal damage by sheer impact. Birdshot is pretty much ineffective against body armor, unless at very close distance.
Also, any high power rifle bullet will cause some damage - we are talking very bad bruises here, or - if you have bad luck - maybe even broken ribs or some other internal damage. Handgun bullets are much easier, but some bruises are inevitable.
There are also some special, better protecting armors (like, for example deck gunner armor - too heavy to walk around wearing it, but you can ride in it), protecting against explosions (for IED disposal personnel) or with additional layers that protect against punctures and stabs (standard bullet-proof vests aren’t good at stopping such threats). Many exceptions apply, but those are basics.
Those suits are designed to protect against fragments produced by detonations of a couple pounds equivalence, at best (say, the size of a briefcase). They don’t do a very good job of attenuating blast pressure of larger decibel pressure waves. You mention a pipe bomb; a bomb suit would work great for that purpose. While there are plenty of suits on the market that will protect against fragments at close range, it is very difficult to prevent the lungs from compressing in a larger event.
Although I’ve been at test ranges that have tested helmets and bullet proof vests for their resistance to shrapnel, I wasn’t directly involved in said tests. I remember fooling around with the equipment before the tests, but don’t specifically remember seeing it after, nor did I know how much or what type of energetic material was used in the testing, or its confinement, so I didn’t really comment on the shrapnel aspect. They had pressure transducers set up in the head and chests of the dummys, though, and although I didn’t have privy to the data, I seem to remember the unattenuated pressures and the mitigated pressures being significantly different.
As Scumpup said, properly functioning guns don’t harness an explosive; they harness a deflagration. Regardless, it’s hardly what comes to one’s mind when bomb or explosives are being discussed.
I treated a helicopter door gunner who was shot once in the chest by what was probably an AK or an SKS. This would have been 1970 in Viet Nam, but I think he was shot in Cambodia. He was wearing what we called a “chicken plate.” It was a stiff ceramic vest much too heavy and bulky to either conceal or walk around in. The steel core of the bullet is all we recovered from the vest. The steel core had entered one side of his vest and penetrated about half way through. Then it followed the contour of the vest around to the other side of his chest. That’s where we found it when we took the vest apart.
His only injuries were a crease on his wrist where the bullet passed as he was holding his M-60 and a huge bruise on his chest.
The shooter (I don’t call her a sniper because she stood up to shoot) was killed by his return fire. We all agreed that she was a good shot. Without the chicken plate, he would have been dead.
When I was in Baghdad, one of my local office guards was shot in the chest from a tall building about a couple of blocks away. He was wearing a ceramic plate body armor similar to what T. Slothrop describes. The shot knocked him down and we pulled him in the office. A doctor checked him out, he seemed fine. He had a glass of tea and a cigarette and went back to standing in the exact same spot. I don’t know what kind of round it was.
An ex sqaddie mate told me that a similar thing happenned to a member of his platoon in Northern Ireland, except that the guy was shot in the head and it was the helmet that similarly protected him.
