All it takes to make this is a few paperclips, an old pen, and a rubber band. first, open the pen up and dump everything out, and then put the lid back on. make sure you take the pen button out too.
Step 2: Join And Insert The Paperclips
Depending on how long your pen is, you may need more. But I used 3 paperclips. straighten the paperclips out, and then wrap the ends together to form a chain. now, insert the chain into the pen.
Step 3: Add A Rubber Band And You're Done!
Now, bend the ends of the paperclip so that you can add a rubber band. after you put the rubber band on, Bend the ends of the paperclips so the rubber band won't come off. it should have a small bit of space in between pen and the rubber band, and the rubber band should be good and tight. now, get a pencil (or the pen part from the inside), and fire! it shoots pretty far, and fast enough that my camera couldn't detect it with a motion sensor. It is hard to aim though, so use it in an open space. Things I've learned from this: Good rubber bands=deadly weapon in multiple ways. My sister managed to shoot me with a pen and It drew blood. She was right next to me though, I doubt it would have happened had she been further away.