This is my first instructable, i am sorry for any flaws and blurry photos.
I take no responsibility for any damage to people, items etc. caused by this device.
Step 1: Materials
You will need:
The thickest rubber bands you can get.(size 109= $5-7 from most stationary stores)
Ideally a small pringles can but anything like that will do. (try to get something that is sturdy)
Scissors or knife
Masking or duct tape (optional, but will increase life of the rubber bands)
Step 2: Tie the rubber bands together.
Repeat so you have two lengths of rubber bands.
Step 3: Making The Ammo Cup
If you are using a thin plastic cup you might want to put tape on the edge of the hole so it doesn't cut the rubber band. (see pic)
Step 4: Finishing Off
Now feed one of the bands through the hole and and tie together.
Make sure the rubber band isn't twisted or uneven where you tied it.