Dude claims at ~14:30 that "Level IV armor will stop a .50 BMG".
Level IV armor is only rated to stop up to .30-06 AP. Even if it were to physically stop the penetration of a .50 BMG round, the blunt force imparted on the body would be enough to cause serious, fatal injuries.
Much like the soft body armor he tested in this video, which technically stopped .45 ACP and .357 Magnum rounds from penetrating, but which you can see allowed such dramatic backface deformation that it would have failed in real testing (and real world use would have caused serious internal injuries, even without the penetration).
I realize that this guy is just messing around for fun, but this highlights the major problem with amateur interweb body armor "tests". They take some armor, hang it from a tree, or put it on a sandbag, or drape it on a mannequin, shoot it, and then claim the armor works when/if the bullet doesn't penetrate.
Actual armor testing involved standardized mounting methods, calibrated backing material, and measurements of backface deformation. Not just "
Did it penetrate? Yes/No"
Because merely stopping the penetration of a bullet doesn't mean it's survivable or that the armor "works".
