Well, if you include pre war M&P's in the question, then the steel in those guns is almost certainly less strong. Improved heat treatment started with development of the N frame .357 magnums in 1935 or so. Improved heat treatment definitely showed up in K frames by the time the Combat Magnum arrived in the late '50s.
The first indication a bad guy should have that I'm dangerous is when his
disembodied soul is looking down at his own corpse wondering what happened.
Yes, but specifically a "M10" is post 1957...
And regarding 38 spl S&W steel K frame revolvers of the modern, post WWII era, nobody knows what metallurgical improvements were implemented, at what date, or in which specific parts.
I was into 10mm Auto before it sold out and went mainstream, but these days I'm here for the revolver and epidemiology information.
Apples and oranges. The 9mm was designed as a smokeless powder cartridge. The .38 was designed as a black powder cartridge, with very low pressure.
Also, the chamber of a 9mm auto's barrel is very thick. The individual chambers in the revolver's cylinder are very thin, especially on the outer side. Add bolt cuts to that and the chamber wall is VERY thin.
Last edited by Alpha Sierra; 04-16-2019 at 12:39 PM.
Hence... "nobody knows" in the general public.
Of course some people in S&W, former employees, or other some people in the industry know about this, or at least partially. I wonder if S&W ever implemented some tests, or did some calculations regarding frame/cylinder/forcing cone strength improvements with improved metallurgy, or if they simply said "lets use a different steel, or heat treat it differently".
The old S&W revolvers had very soft steel in the cylinder and barrel, very easy to peen.
From a manufacturing production standpoint it makes no sense to use differing steels or heat treatment processes on an otherwise identical cylinder/frame. The only difference is which reamer you finish with or some pretty minor window sizes in the frames. It makes much more sense to keep them all the same for tooling life purposes.
But as has been said, we just have no way of knowing what they do.
Buffalo Bore claims to hit the velocities you are talking about, 125 @ 1258 FPS from a 4” revolver.
https://www.buffalobore.com/index.ph...t_detail&p=109