This happened out at my land today. I about soiled myself. All the culprits are in the pics. Tell us what happened. No prize, just kudos for being sharp.
That didn't take long. My backpack was next to me in the polaris. The water bottle was in the backpack. I don't know if the heavy condensation played a role. I was driving along when it went off. My 1911 was in a separate pocket in the backpack. I was initially worried it had fired but I was pretty sure I hadn't chambered a round. As you can see the primer isn't dented. The water bottle survived. You can see the crack in the battery by the positive terminal from the detonation. I didn't even know I had a loose round in the backpack. Luckily, it was a fairly mild "41 special" load.
You could have been in big legal trouble if your buttocks were sweating profusely and the battery had come in contact with them and the shell, causing the round to detonate. That would have been a clear case of...ass salt and battery. Sorry, I deserve a beating for that!