I was going to post this but you beat me to it. Great book, can't wait for the movie. It has a great message and typical fat lazy Americans are usually too busy watching 8 hrs of television to pick up a book that they might actually learn something from. Maybe this will get Rand's message across.
Full propane bottles with a flare taped to the side. Also giant balloons filled with acetylene. Try some tracers and incendiary rounds for extra pop! Remember, safety first, so always where your PPE. Happy shooting!