"there's a video or two out there of a guy in body armor voluntarily being shot by a high powered rifle at a distance of a few feet. He stands on one foot as he's shot and doesn't even lose his balance."
Why would he? The guy shooting the rifle didn't fall down... same energy is directed on both directions, fore and aft, every time a rifle is fired. If it doesn't knock down the shooter, it ain't gonna knock down the recipient.