How do you make a pen gun?

you simply get your pen and unscrew it all, you need a pen which doesnt go thin on the bit where you write. you get a thick elastic band and put it on your pen covering over 1 open end about 1 cm away from the end. celotape it on with alot of cellotape then get the bit with ink in put it back in pull the elastic back and fire.

u freaking newbthats not how u do it