Unfortunately S&W doesn't stock cylinders for the 25-2 any longer - and the cylinder used for the new-issue 45 ACP's isn't compatible. They'd advised contacting Numrich, but they don't have any either.
Any other leads will be appreciated.
I should slug the barrel, per HB's suggestion, and get a better idea of the dimensions I'm working with. But I'm not casting my own bullets, and likely won't, which is why I'm interested in new cylinder.
The revolver is actually decently accurate to 25yds w/ jacketed bullets, and it's OK w/ lead, but doesn't hold groups at 50yds well w/ either.