I have discovered that expended wax bullets such as these used in "cowboy action" shooting:

Spitfire Wax Bullets

can be recycled into pretty good emergency fire-starters. I just wrapped one in a used but dry paper towel, and the towel burned for 10 or 15 seconds, but the expended wax bullet burned for about 3 minutes. These little projectiles can be easily captured by any thin plywood-ish backstop.