 There's a difference between cover and concealment. Cover will stop a bullet, but concealment only hides you. Most lecterns will not stop bullets, especially AR-15 bullets. But I'm pretty sure this lectern was special because it was designed just for this occasion. Anyone who's ever been in combat knows this saying, when the bullets start flying, you get small real fast. You get down low, you get behind something, it will stop a bullet until you're in a position to return fire and take out the enemy.