As I stated earlier, I simply don't have the "chops" to engage in a learned debate on this subject, however, do think it worth noting a couple of things. My memory is that most of what I have read from Saxon Pig refers to medium frame revolvers, mostly Model 10s. Checking the link that Guillermo provided confirms that, at least in that article. He certainly does not seem to ever refer, at least in my memory, to small frame snubbies, especially small frame snubbies with alloy frames. Apples and organges as far as I can tell.
Additionally (and here I am in deeper water regarding my own smarts on this), he says in the article that was linked that the SAAMI upper limit for .38 Special is 21,500 psi. It is my understanding that for years the upper limit for .38 Special was 17,000 psi and plus P was 18,500 psi. More recently some list the upper limit for plus P as 20,000 psi, not 21,500. Speer lists their 135 grain load as 21,500 psi Maximum Average Pressure in the technical bulletin but an email from Speer told me that
the Speer 38 +P 135gr. Gold Dot HP ammo does not exceed 20,000 MAP (Maximum average pressure), according to the Engineering drawing for this product. 21,500 psi is the "Maximum Probable Lot Mean", (meaning 97.72% of individual pressures in a test will be below this level).
My concern here is that older snubbies, esp alloy ones, were rated for standard pressure ammo (or limited plus P) in the days of lead 158 grain LSWCHP+P ammo which would have been spec'd at 18,500 psi. At least some of the current plus P is spec'd to at least 20,000 psi. If the guns were marginal for 18,500 psi, it seems logical to me they would be, uh, even more marginal for 20,000 psi. Personally, I agree with Old Fuff in that it is not my concern what other people shoot in their guns. It is, however, of concern to me what I shoot in my guns.
I am completely willing to be convinced otherwise but the usual argument seems to be merely that old loads were strong and new loads are wimpy, so there. So until I can unearth actual data, I'll probably err on the side of caution. That's what my lawyer seems to suggest.