Off the top of my head, 3-inch, 5 1/2-inch, and 6-inch were common. John Jovino may have sold some limited editions with shorter barrels but can't be certain of that. Don't know what's in the current Smith & Wesson catalog.
Sure is a good way to do big-bore revolvers, the .45 ACP.
A friend's most excellent Model 625 Model of 1989 3-inch (top).
An example of the one that started it all. A World War I military contract Model 1917 Smith & Wesson .45 ACP revolver.