black029.... you may safely bet every sugar cookie ever made the Redhawk cylinder has greater diameter than that of the S&W M-29/629. While diameter of Bill Ruger's Super Blackhawk is similar to the M-29, the Ruger represents vastly greater durability under sustained magnum fire. While I would rate the cylinders close in strength, as in pretty damn strong, the fact of SBH durability proceeds from the "solid" single action cylinder frame, with greater mass in lockwork.
When Ruger set out to make a double action .44 Magnum, he at once set to eliminate the traditional DA sideplate and increase mass. To increase diameter of barrel socket in frame he offset the ejector rod below the axis of the cylinder. The cylinder latch (cylinder stop) was made heavier, stronger, and able to time with a heavier spring. These are a couple of details which make the Redhawk and its offspring Super Redhawk far stronger under heavy loads than the S&W.
The Dan Wesson Arms Model 44 (.44 Mag) also takes advantage of the solid frame DA concept.
A proper S&W M-29 or M-629 is a thing of beauty, accuracy and long service life. Just don't let it feed at the same trough as a Redhawk or Super Redhawk.
David Bradshaw