i want to share one of my projects with you, it's a pengun made out of a ........PEN!

I can pump it up to 435psi (max of my pump;-)). It's got a tiny QEV inside, triggered by a shrader valve. The cap hides the valve. It has got a small pin inside, that releases the air, when you press it onto the valve.

The barrel is a 2mm aluminium tube. It can fire small steel balls (from ball bearings), toothpicks and nails.
Here's a video of firing it=)
If you've got any ideas, criticism, questions, suggestions, tell me!:)