This Instructable shows you how to make a mini airsoft machine gun.
Step 1: Drill Holes
Drill a hole in the cap of a pill bottle and also in the bottom of it big enough for a pen to just barely fit in.
Step 2: Insert Pen Tube
Insert a pen tube into the bottom of the pill bottle
Step 3: Fill Bottle With BBs, Blow Through Hole in Lid
Now, fill the bottle with bbs and blow through the hole in the lid.