The cylinder has a lot to do with the accuracy of a revolver - more than any other part of the revolver. The bullet starts its trip from the chamber in the cylinder, jumping from the cartridge case to the cylinder throat, then it has to pass through the throat across the B/C gap, forcefully align the cylinder to the barrel by ramming into the forcing cone, then it's finally free to run in the rifled bore. If anything bad happens through any one of those steps, then the bullet will not be able to recover in the rifling to repair its accuracy, the damage is already done. In other words, the cylinder determines the presentation of the bullet to the bore, if it's good, it's good, if it's not, then accuracy suffers. Just like any sealed breech firearm, the chamber to bore relationship is critical for a revolver.
So if a chamber isn't concentric to the barrel bore, or isn't coaxial, and if the lock-up isn't properly aligned, or if there's excessive headspace or excessive b/c gap, your accuracy will suffer. If the chamber throats aren't properly sized, your accuracy will suffer (Rugers are notorious for tight throats).
Without going into over-bearing detail of how deviations in any given specification would affect accuracy - the simple answer is that the cylinder machining quality and fitment is more important than the barrel itself.
What in particular is your ACTUAL question? Did you transplant a cylinder into a revolver? Do you have a "convertible" model that isn't shooting well with one cylinder? If your accuracy is suffering, what in particular is happening?