Since I don't know your firearm I don't want to offer advice but remember you are dealing with a near clock-like mechanism where everything is tied together, change one thing and it effects something else.
An example might be a manufacturer's flaw on the racket teeth- one is a little off which creates an indexing problem on only one chamber. Let's say the hand is lengthen. That probably won't solve the problem. in fact if it makes the cylinder start rotating before the bolt fully drops- it can create more problems. On some handguns the end of the hand starts the cylinder rotating but then slides off the ratchet teeth and the side (thickness) of the hand keeps moving the cylinder into the final position so lengthning the hand does nothing.
In short, I'd try to re-state what the problem is in very fine terms, plus the model gun, etc and ask lots of questions and wait for a lot of answers and then think about what needs to be done prior to making any changes.