Morn'in Hairy Chest,
I cannot answer your question except with the following. When the model 29 "classic" first came out, Smith and Wesson's own ads said that the "Classic" was a firearm built for "sustained" firing of magnum .44 loads.
Seems to me that the wording of THEIR ad indicates they knew of issues with the origional model 29. Why else would they use a term, "sustained" indicating the earlier 29s were not up to continued or sustained firing of such loads without some issues cropping up?
This was, after all their ad, OK'ed and paid for by S&W.
Now, I have not been a S&W fan as I have been a RUGER fan, as I like the "little guy" - RUGER was the little guy back in the 60s - 70s when I began buying their products - who one ups the big boys with a better product.
However, other then the period of time back in the Clinton days when S&W sold out to some bad ownership/management and turned out questionable products for a period of time, S&W has turned out a fine products.
But for me, Integrity is a really big selling point. I'll buy the strength and integrity over the beautiful finish and factory tuning even if I must, pay a small amount to bring the function up to first class. Believe me, I have put out little money over the years doing that and have owned and sold almost as many RUGER handguns as the 7 I presently own.
There can be no question that if fired to distruction, the solid frame RUGERS will trump the S&W with their side plates. That is just a simple and easy to see fact. Solid trumps a screwed on side plate and over time must show it's advantage.
However, I don't want to be the one shooting either one of them when they let go. Will not be a pleasent experience!
Even owned one S&W, a model 41 target pistol. Should have kept it. A thing of beauty and function, but of no better function then the 2 RUGER Mark II I currently own, and likely not as tough.
If I wanted a small frame .357, it would clearly be the SP101, but if you have fired full blown .357 loads in that light handgun, you will know it is not a fun thing to do. PERIOD!!! NOT FUN. But as a carry gun which will see few if any more casual firings of .357 loads, I find great comfort in the fact that it will survive any needed firings of any such loads and still be functioning after the fact.
Your question will never find a "real" answer as long as there are S&W and RUGER fans.
Either way, you are far ahead then if you bought any of the other brands such as Taurus, Rossi, etc.
Crusty Deary Ol'Coot