Yikes! OMG, someone threw a bullet in the burn pile.

I was burning some trash, just now, and when it had burned through the bags, I went over to make sure everything had burned ok. While the bags had been burning, I heard a "Pop" and knew it was from a plastic bottle, as it continued to burn, I had later heard a somewhat louder "Pop" or "Bang", but I was far enough away from the fire at the time, I just assumed that it was from another plastic bottle, but whatever it was, it had startled Oreo and sent her running under my father-in-law's stationary work truck. I found an empty cigarett box, either my father-in-law's or my brther-in-law's, and pushed the top of it onto a flame, I then stepped away from the fire to clear the smoke, and went to the front of the fire, where I found a magazine that hadn't fully burnt. I started to push on it to peel some of the layers away, to allow for easier burning, seeing the empty box had burnt some at the top, I pushed it up so that the bottom was over the flame and stepped away, again to get away from the smoke. As I was getting ready to step back over and work with the magazine, again, I heard another loud "BANG". I gasped, jumped, and stopped where I was, as I saw something leap out of the fire, although I couldn't quite tell where from. I looked down at the ground and found, about a foot away from me, what at first looked like a burnt banana peel. I took the metal beam I was using to stir the fire with and tapped it. It was hard and solid I rolled it over and realized it was a bullet and the tip had exploded in the heat. I looked up at the burn pile, and there was a round hole in the center of the cigarett box. I'm not sure if that's from the bullet having been in the box, or if that hole was naturally made by the fire, and the bullet was hidden somewhere under the ashes, though, because, as I said, I can't be sure where the bullet popped out from.