I think that the military body armor will stop a rifle round.
Really? Even a heavy .30 caliber? I sure wouldn't want to be on the other side of the vest when a .375 Magnum round slammed home. It would probably feel like getting hit by a car. Painful and probably still injurious, but better than not having a vest.
Most of the “flak jackets” are mostly for concussion and shrapnel. Some small arms. To be bullet proof you need a minimum of Level III or IV ceramic or ballistic steel plates (too heavy to wear) that fit into pockets in the vest.
Your vest can be “bullet proof”, but the energy from the bullet is still going to be displaced into its target.
Maybe a low power round like from an AR-15, but not a full power round, if he was using an actual sniper rifle. I’m not sure what gun the guy in Dallas was using though, I’ve seen conflicting reports.
Maybe, Maybe not. Either way I do not want to be wearing it if a round from something like my 30.06 hits it. If it doesn’t kill you it will BREAK YOUR RIBS and you will wish you were dead after you pick yourself up off the ground if you are able.