I was watching an episode of CSI:Miami the other day…….not a bad show, BUT: At the scene of a shooting, some 9mm was found that was so corroded the headstamp could not be read. (They showed brass cases and loaded rounds with brass cases, which appeared quite shiny when first discovered). Taken back to the lab, the cartridges were cleaned on the base with acetone to determine the headstamp. It was found that the cartridges were imported into the US from Eastern Europe, which is illegal. When one cartridge was disassembled, it was found to contain black powder, which is very dangerous. This is because as the cartridge ages, the black powder is going through a continuous chemical reaction, causing it to get ever and ever hotter. When jostled or dropped, this chemical reaction increases to the point that the cartridge explodes. (Remember, a lot of these had just been fired at a crime scene, so why didn’t they “go off” when jostled in the firearm, let alone chamber with all the corrosion on the cases) In this case, when a cartridge rolled off the table and dropped to the floor, bullet pointing upwards, it went off and blew a fluorescent fixture out of the ceiling, which came crashing down on the table in flames, setting the acetone used to clean the case heads on fire and darn near burning down the lab.