Roy is right in the sense that the Uberti cylinder and the Pietta cylinder are different enough to be non-interchangable once fitted. You can make an Uberti cylinder fit a Pietta gun and vice-versa, but once fitted, the original cylinder won't time up right. There are little differences like the location of the rachet notch for the hand, and the width and location of the locking bolt that make it unwise. I have an R&D conversion in an Uberti that had to be fitted at Taylor's, and to work, it has an Uberti cylinder and a Pietta backplate., so each gun is different. In the Colt type it would be the same. If both cylinders are the same brand, they either drop in and work or fit with so little modification that they are interchangable without problems.
