Pocket Sized Lego Gun

This is my mini Lego gun its simple to make and only takes 5minutes top to make. 
The things i like and specifically wanted in this little gun was it to shoot quiet far and to be really strong when it hits the target.  

hope fully you can make the gun from the pictures its a little hard to explain how to build  

the rubber band is easy to put on the gun once u hav it on u place the washer (bullet/ammo) on the up side down T and put the rubber band over it and then to fire pull the T down until the washer(bullet) flys off.