2nd Gen Colts were produced as rough parts by Uberti (Italian) and finished by Colt stateside. Colt paid much more attention to the exterior finish than the internals. Uberti revolvers are notorious for having a poor arbor-to-arbor recess fit (to this day), wherein either the arbor is too short or the arbor recess is too long, or a combination of the two. Rather than get into a long discussion about this, suffice it to say that the barrel/cylinder gap should be changed by how far the wedge is inserted, and also how much pressure is needed to secure the barrel to the arbor in the initial state with no modifications.
It can be fixed if you have a bit of skill with hand tools and comprehension of the written word. Click on the link below and choose the 4 .pdf files concerning Uberti Open Top Revolvers and download them.
PettiFogger_Files directory listing (archive.org)
This says it all as to my point. Tom, you need to refer to these files also. The barrel cylinder gap should not change no matter how far the wedge is driven in. If changed, you will need a feeler gauge to set the barrel/cylinder gap every time you reassemble the revolver.
Regards,
Jim