Aside from huge rifles like .50 BMG and the like, that is. NIJ 0101.06 Level IV specifies that the plate must be able to stop .30-06 M2AP at 2,880 fps. I’m case you’re not familiar with M2AP, it is a copper jacketed projectile with a hardened steel core. It was issued during WWII originally as special purpose ammunition, as is typically the case with armor piercing ammo, but eventually replaced M1 .30 caliber FMJ due to its superior performance. Joes loved it because it could get through almost anything and it was quite terminally effective. It’s so good at getting through barriers that armor designed to stop M2AP has been able to stop almost anything else thrown at it. YouTube armor testers such as Buffman R.A.N.G.E. and The Wound Channel have determined that .300 Winmag is no match for level IV and only one really hot .338 RUM load was able to get through an Armour Wear Level IV.
But then Buffman managed to get his hands on a unicorn and a pegasus. M993 AP 7.62x51mm NATO and B32 API 7.62x54mmR ammunition. He tested each against AR500Armor.com’s Level IV plate and RMA’s Level IV plate.
Now, right up front, we should point out that neither plate is rated for these threats. Both plates conform to NIJ Level IV standards and they have been shown to stop .30-06 M2AP in other tests, along with many other threats. With that out of the way, there are a couple things to take away from these tests. The first is ‘Merkah, dammit! Damn commies lose, we win. The M993 dramatically outperformed the B32. The second big takeaway here is that, no matter how good armor is, there’s always something that can defeat it. Not only was the M993 capable of perforating both plates, it carried a great deal of energy into the ballistic gel block and passed all the way through. You can also get a really good view of what is happening in this “naked” video of the RMA plate.
What does this mean in practical terms, though? It means that if you wear armor for a living or keep it for emergencies, you should be aware that it isn’t an enchanted aegis. There is ammo that can defeat it. It’s also important to consider that it doesn’t cover your face. Armor is intended to increase your chances of surviving in the event you get shot, but you should probably mainly try not to get shot.