First off I want to say thanks to Pettifogger for his great articles on cap and ball pistols. I read his articles and applied his method of fixing the short arbor problem. There is nothing new here, other than I did it on my little Uberti 1849 pocket pistol and made my own button.
After reading Pettifogger's article I pulled out my 1849 to check the arbor, sure enough it was short. This is clearly visible here:
I didn't have any of those Dillon buttons he recommends, but I do have an old 12" Altas lathe, so I proceeded to make my own button. I know that not everyone has a lathe, but this shows just another good reason to put one on your wish list.
But this little pistol is small, so I needed to scale things down a bit. The arbor is .305" diameter. So I made the button the same size. I decided to drill a 5/64" hole in the end of the arbor for the button's stem. I made the stem about .002" undersize in the hole.
The arbor is about .080" short, so to start out I made the button about .100" thick. I wanted it to be oversize to start with, then I could work it down to fit. Here is the oversize button ready to be fitted.
Following Pettifogger's guidance, I very carefully marked, drilled and chamfered the 5/64" hole in the end of the arbor.
Test fitting the button with feeler gauges showed that it was about .020" too long.
So back to the lathe with the button where I carefully thinned the head .005" at a time. I did this several times until I had it where
the barrel matched the lower frame perfectly.
Here is the finished button, the end chamfered similar to the original arbor end. It was then set in the arbor with medium strength Loctite.
Next I put it back together and found the wedge was just a little too wide. It would go in, but not enough to protrude out the right side. So with a fine file, I carefully narrowed the wedge until it would just protrude out the right side a little bit. The cylinder gap is now even top to bottom and measures .008" using a feeler gauge with the barrel held back against the hand spring.
I'm very pleased with the results. I hope you all find this helpful.