“Lang kept at it until everyone had had a turn shooting an AK-47. Then he said, "This weapon can do one other thing I haven't shown you yet. When you move the change lever all the way down instead of to the middle position, this is what happens." He stuck a fresh clip in the repeater, turned toward the target circle, and blasted away. He went through the whole magazine almost before Caudell could draw in a startled breath. "Good God almighty," Rufus Daniel said, peering in awe at the brass cartridge cases scattered around Lang's feet. "Why didn't he show us that in the first place?" He was not the only one to raise the question; quite a few shouted it. Caudell kept quiet. By now, he was willing to assume Lang knew what he was doing. The weapons instructor stayed perfectly possessed. He said, "I didn't show you that earlier because it wastes ammunition and because the weapon accurate past a few meters- yards- on full automatic. You can only carry so many rounds. If you shoot them all off in the first five minutes of battle, what will you do once they're gone? Think hard on that, gentlemen, and drill it into your private soldiers. This weapon requires fire discipline- requires it, I say again."”

Source: The Guns of the South (1992), p. 31