[mykeal]

Let's see if I can help a little.

The Kershaw cartridge is created by first milling a ring off the back of the percussion cylinder that leaves the center containing the ratchet teeth intact. The depth of the material removed is to just short of the chamber depth, so that the end of the chamber is left intact with the nipple hole remaining in place. The second picture shows the result, along with a new ring that goes in place of the removed material. This new ring contains a single firing pin, seen at the top.

Short tubes, made from gun barrels, are inserted into the front of the cylinder; their length is such that the ball rests against the end of the tube and is just short of the chamber mouth. The ball is now resting on a smaller diameter combustion chamber. The tubes can be seen in the picture below.

The balls are seated in the chamber first. Then the cylinder is turned over and smokeless powder is loaded into the tubes through the holes where the nipples used to be. Shotgun primers are then loaded into the nipple cavities (I'm not exactly sure how those cavities are modified, but it suffices to hold the primers).

Finally, the new ring is installed on the back of the cylinder. The ring is stationary with respect to the frame; they cylinder rotates within the ring, so that the firing pin in the ring lines up with the primer on the chamber that's in battery. The third picture is one of the ring installed on the back of the cylinder, or how the hammer would view the assembly.