I have seen a lot of tutorials that teach you how to make a pen gun. Unfortunately I did not have a decent pen on hand to make said weapon. So I used the materials available to make my very own pocket sized BB gun. This miniature weapon is very powerful for it's size, and is very easy to make.
Step 1: Materials
To build the BB gun you're going to need a pair of scissors, 3 plastic straws (the straws I'm using are 19 and 5/8th inches long and and a half inch in diameter), Scotch tape, tacky glue (or any other strong glue), a pair of plier-style cutters, a paper clip, an Exacto knife, a cork, a diffuser reed (if you can't find one of these just wrap a shish-kebab stick in duct or electrical tape for thickness), a rubber band (I used a #32 rubber band), and a large kitchen knife (optional).
Note: The kitchen knife and the rubber band aren't in the picture