Step 4: Assemble the Hammer
The "hammer" for the gun will be a bead threaded through the slice in the barrel. Use the thin copper wiring. Sliding the bead into the barrel, take one end of the wire, and twist a loop onto it. I used the end of a drill bit to make the loops large enough that I could easily feed a rubber band through them. Then, slip the wire through the slit in the barrel, through the bead, and out the other side. Now create your second loop on this end.
All said and done, from loop to loop, it should be approximately one inch wide, as seen in Image 1.