Don't know about Uberti changes over the years but here are the dimensions on my 1862 Police Manufactured in 1971.
Chambers .376, .376, .377, .377, .375 measured them all 3X same results each time.
Groove diameter = .377 Land diameter = .368 Slugged the barrel with a .380 round ball.
6 lands and grooves.
1:20 twist rate. This barrel is 6 1/2 inches long the grooves turn +/- 1/3 of the barrel length. Measured by forcing a tight cleaning patch down the barrel and marking how far the rod turned.
I haven't messed with this revolver much yet. Shot 3 cylinders through it one time. It was all over the place. I was using .375 rb with a wad since that was all I had. It's a wonder the balls didn't fall out after first shot. I now have .380 rb so that will help a lot.
Now that I've looked at it closer this revolver is in remarkable condition considering it's age. I should put up some close up pics of it.
Thanks for making me take a closer look at it rodwa.