Many years ago, Elmer Keith reported on some tests run by a friend of his. The fellow wanted to see whether the Ruger Super Blackhawk was as strong as the S&W M-29. He loaded progressively hotter ammo until one blew. The Ruger cylinder blew before the Smith did.
However, the Ruger digested loads much more powerful than would be used by any sane person. Certainly well in excess of factory proof rounds.
The real choice between those guns is in how fast one might have to reload, and how they handle recoil. And which best endures NORMAL ammunition over the long haul. On that basis, the Ruger is the better choice.
I own both S&W and Ruger guns, and am very fond of each.
I guess the moral here is that you can blow up either if you aren't a very careful handloader. Use factory ammo or equivalent, and either will give long, useful service.