.50 cal near misses ripping limbs off is total bullshit and an urban legend. It's been tested plenty of times and it's complete hogwash. Think of it this way, if a bullet were creating such a powerful shockwave, where is that energy coming from? Wouldn't the bullet slow down incredibly fast? A bullet is designed to have as little shockwave as possible, as any shockwave dissipates energy that is subsequently not delivered to the target.