Does each cylinder come with its own crane? If not, you have a problem because Colt cylinders were not made to be interchangeable or even to be removed from the crane except by a gunsmith with the proper tools. I suspect you have a gun made in one caliber, for which a previous owner purchased a second cylinder with the possible intent of making interchangeable cylinders until he found out the problems in doing so.
If you do decide to go ahead and install the other cylinder on the crane, be aware that fitting a cylinder is not an easy task, even for an experienced gunsmith. And you must have the properly fitted ratchet/extractor.
I suggest you live with the original chambering and forget the idea of swapping cylinders.
Jim
