This has been an informative and interesting thread for me. I am considering buying a Bianchi 2800 holster to hold a Ruger SP101 4.2-inch barrel. While I have essentially no doubt of its ability to handle slightly longer 4.2-inch barrel, the SP101 is smaller than the "K" frame Smith & Wesson for which it was designed. Its cylinder's diameter is approximately 1.34 inches while "K" frame's cylinder diameter is 1.446 inches.

Does its cylinder pocket plus spring retention allow the holster to maintain snug control of the SP101?