The K-3, Shotgun Internals, and The Failed K-4
As for the K-4:
Everything worked the way it was designed to work, but certain mechanisms (the trigger and the BTS) required a lot of force to function, thus reducing the amount of tension that would be even remotely practical to use on the bow. It was a good attempt and I have learned a lot from it; things that I will take with me as I move on to bigger and better guns.
Here's a video for now, and I will explain everything in depth as soon as I can.