THIS IS NOT TO BE USED AS A WEAPON! DO NOT BE STUPID AND SHOOT AT ANYONE OR ANYTHING ALIVE! I AM NOT RESPONSIBLE FOR ANYTHING YOU DO WITH THIS!
This instructable will show you how to make a simple pen gun that will shoot just about anything out of things that you can find at home or in school.

Step 1: Get Materials.

You will need:
A bic mechanical pencil.
A bic pen of any color (with the cap)
2 rubber bands
scissors

Step 2: Disassemble Your Materials

First: Take apart the pen by removing the head and the ink tube. You don't need to remove the end cap. Remember to save the cap!
Second: Take apart the pencil. You can do this by pulling on the head until it comes off, or if it doesn't, just snap it off. Then take out the inner tube and throw the rest away. Take the little black thing off, so you have just the tube.
Third: These are what you need at the end.

Step 3: Assembly

1: Poke out the small round thing at the end of the cap.
2: Post- poke.
3: Jam the cap as far onto the pen body as you can without breaking it.
4: Measure where to cut in accordance with the inner tube and the pen.
5: Cut at the mark.
6: Put the inner tube inside the pen and cut a notch in the eraser of the inner tube.
7: If needed, you can widen the hole in the pen cap with the front part of the pencil.(just don't push too hard and break the cap.)

Step 4: Add Rubber Bands

I usually use 2 rubber bands doubled over, but three can be used.

Step 5: Loading and Firing

To load, pull back on the tube until you hear it click.( you may have to angle it up.) then insert ammo of choice. (gum wrappers, paper, etc.)
To fire, push down on the back part until it snaps back into place.