Watch this video to see how to make a baking soda and vinegar bomb. That is all the ingredients. the only other stuff you need is a bottle and piece of plastic bag. they explode on contact to a hard surface (or gun) and sound like a 20ga going off. Be careful with this one, I am not responsible for anything that you might do with this. Don't forget to go to www.dostuffright.weebly.com for more videos or if you want to Donate through Paypal.
EDIT: here is a newer video with better quality.