Wheel Shooting Knex Gun Very Powerfull

Hello guys
I was making a knex gun and i thougt: why don't use wheels as ammunition ??
So here it is :

Step 1: 'The Barrel'

Step 2: The Handle

Step 3: Trigger

Step 4: Extra

Step 5: Attaching the Handle

Step 6: The Rubber Bands

DONE !!!