I know a guy who used to shoot into a horse trough, and pick the bullets up off the bottom to see how much they expanded. My recollection is that he never had a bullet punch through the bottom of the tank, so the 24" penetration extreme is probably about right. I'm a little surprised at the 50 BMG. Must be some sort of A-Max targe bullets. The military rounds are made to shoot through aircraft and armor. I can't imagine them coming apart in water.