see pictures: pull the pin, and pull the trigger to fire! If you want to shoot paper balls or pencils just pull back the pin, insert the things you wa...
Step 3: Magazine
This will be the magazine. Take 2 blue rings, 2 white parts and a grey part. (not the dark grey part)
(it's hard to see, but the grey part is between the 2 blue pieces to stop the balls from falling down. But make sure it's on the good side or else the magazine won't close and balls will shoot to all directions.)