We were pulling targets for an Infantry Team Match in Beaumont (never volunteer) while a new shooter was shooting a M1A rapid fire at 600 yards. I watched him hit my target with several shots that began to go lower and more to the right as his right elbow slipped in prone position. He next hit the target to my right and then the metal frame. The bullet came apart and hit 3 of us. No one was seriously hurt, but we could have been. A piece of the bullet glanced off of my hat bill (always wear a hat with a hard bill and safety glasses in the target pits). The hole in my arm was made by a piece of bullet jacket that bounced off of my humerus, It only weighed about 2 grains and penetrated 3 or so inches into my arm. I had it removed a couple of days later.
Upon investigation, it turned out that the target frames were traveling up too high and the protection berm had suffered some settlement. The target carriers were of a cantilever design and the counterweight had made a depression allowing the target end to go above the protection berm. Palo Alto's carriers are of a different design so this type of situation will not occur.
Oh yeah. Those are awesome. But if used wrong they won't do anything but burn the pt. LOL and you can burn capillarys closed but they won't work so good on an artery.