Great article! I just went through this on my new Pietta 1860 Army regarding fitting the bolt.
What I learned was that, at full cock, the hand was actually holding the cylinder against the bolt, but that on two of my chambers (the two with the narrowest locking notches) the bolt wasn't fully dropping into the slot. As the hammer began to fall, and as it took the hand down with it, the hand would drag against the ratchet and actually rotate the cylinder out of battery a little.
I measured up all of the notches per the instructions in this writeup, and determined that I needed to remove a little metal from the bolt. I followed the instructions posted, and tested the bolt manually in each of the cylinder notches until I got it to fit each one. Next I reassembled the action, but I left the hand out! I could then bring the hammer to half-cock, rotate the cylinder to just slightly short of being in battery for each chamber, then go to full cock, and manually rotate the cylinder the last little bit and feel the bolt drop into each notch. I could then test the feel of the lock up knowing that I wasn't being fooled by the hand partially holding the cylinder into battery.