Standard class 1,2, and 3 types of body armor only stop shrapnel and handgun rounds to varying degrees. There are different kinds of plates you add for knives and another for rifle rounds.
Knife plate is just hard plastic or sheet metal coated in a rubbery plastic to keep the metal from wearing through the pocket in the vest.
SAPI plates are for high power rifle rounds and are a pressure formed ceramic that's about 3/4 to 1" thick with a layer of Kevlar adhered to it to keep it from fragmenting when hit kind of like the plastic in windshields.
They are working on ways to lighten and increase the flexibility of the heavy armor. ie dragon scales, some sort of reactive gel, and a few others.
BTW ever seen what hi-velocity rounds do to squirrels or even prairie dogs. assault rifle rounds are made the same way as an example a .223 or 5.56x45 round fragments when it hits any kind of resistance this is to maximize its wounding capability, it basically explodes on impact causing massive trauma and blood loss. The tiny critters mentioned above explode for this very reason.
In the case of the 50 cal you have three types of rounds fragmentation for soft targets, armor piercing/steel core, (military only) and incendiary (tracers) that have a tendency to catch things on fire and not much else.
My guess they were using the standard lead core copper jacketed round which = hi-velocity fragmenting.
Last edited by xm20k (2006-12-03 23:45:06)