Things You'll Need
Instructions
Cut the neck off your plastic bottle. Recycle the rest of the bottle, or use it as a planter, so you don't waste it.
Stretch the balloon with your fingers and inflate it halfway several times to stretch it out.
Slide the balloon through the neck of the bottle so the open part of the balloon and the mouth of the bottle neck are on the same side. Hook the mouth of the balloon around the edge of the bottle's mouth.
Hold the mouth of the bottle up and drop a BB into the balloon. Grab the BB through the balloon. Aim the gun, and stretch the balloon back through the bottle neck. Let go to fire your BB.