I've got that Second Chance video. He stands on the bow of a boat and has his father (I think) zap him a handful of times with an SKS loaded with steel-pin ammo. The bayonet is the only thing in between him and the muzzle. After a bunch of rounds, he jumps into the water. Turns out that particular vest was for the Coast Guard, and had to be a life preserver as well.
In anther scene, he has a guy open a box of GI ball 7.62, load a mag, pop it into an M1A (or M14), pop a few into the ground, and while Davis stands on one foot, with his hands clasped behind his back, the guy shoots him numerous times from about a foot away. While the rounds are going off, Davis is talking to the camera, balanced on that one foot.
Hollywood has done well to make everyone think the impact of a round picks you up and tosses you through a plate glass window 10 feet away.