My 1851

[Ringo]

I am sorry I have no G&U, and I will very probably never have one.
Now, the G&U were made back in the very late 1950s and early 1960s, more than 50 years ago, and were made by skilled craftsmen. Nowadays, Ubertis are machine made, under computer control. The resulting product just cannot be the same.
Here is a picture of the Gregorelli workshop back in the days. I believe parts made and adjusted this way cannot be interchangeable with parts made today.

[LonesomePigeon]

I don't have and Uberti but I do have a 2nd Gen F-Series 1851 Navy which are said to be made from Uberti parts assembled in the USA. The cylinders do not interchange with a drop in fit but they seem close. I don't know if one could be made to fit by a qualified gunsmith. One thing I can tell you for sure is that the GU cylinder will not fit on the Colt 2nd Gen because the diameter of the arbor on the Colt 2nd Gen is too large. The Colt 2nd Gen cylinder will fit on the GU but there was a lot of resistance when I tried to cycle it so I did not want to force it. I hope I am explaining it right. Here are my measurements but they might not be totally accurate since I don't have much experience at this sort of thing.

Colt: Diameter - 1.534 to 1.539(it was hard to get a consistent measurement).
Length not including ratchets - 1.702
Length including ratchets - 1.826

G&U: Diameter: 1532
Length not including ratchets - 1.703
Length including ratchets - 1.820

[johnod]

Thanks, good info.
Save me some money too.

[LonesomePigeon]

A couple things about these GU 1851 Navy's if you are thinking of getting one to shoot. I don't know if it's this way for all of them but I had a hard time finding caps that would fit. I believe mine was possibly made for #9 caps, which are no longer made. Remington 10's, Remington 11's, CCI 11's and RWS 11's just fell off. I never did get to try CCI 10's but I suspect they might work if you pinched them. A lot of people pinch caps but I still think it's risky.

I switched out the nipples to one's that take #11 caps but that didn't work because 11's are so big that they would scrape the side of the recoil shield. In the end I had to file down both the nipples and the recoil shield and that made it work.

[DoubleDeuce1]

The G&U 1851 that I have is a shooter.  I do have to pinch the caps to fit the nipples. But now I just use whatever size caps I can get my hands on. That is the way it is...

[Fingers McGee]

While I haven't tried to put a contemporary Uberti cylinder on an older G&U.  It should work with minimal to no fitting.