This is a simple gun made with Lego technic pieces. It is inspired from http://www.youtube.com/watch?v=dLSfBnGj2VQ. I have made some improvements to increase its range and added a second shot to it.
It fires the rubber bands about 15 feets.
-Varad, 7years, Bangalore, India.
Step 1: Parts Required
Step 2: Assembly Steps
Step 3: Firing
Insert your index finger in the trigger and fire by pulling. You can fire twice. See video here: http://www.youtube.com/watch?v=AWN7X6WMOS4