Jackrabbit, you are correct for the most part.
I'm not going to pretend to know how certain manufacturers do certain processes or what different steels are used for what parts . . . that's not my job . . . ! My job is to make them work better, more efficiently, easier and with minimal wear over the revolvers lifetime. Therefore, I do certain things that I have been trained to do by those that know (not "think" they know). I learned from the same person that taught Eddie Janis (of "Peacemaker Specialists " fame) for which I'm eternally grateful!!
As stated before, you can stretch a hand, but to make sure you don't crack or break it, you soften it. When done, you re-harden it. Even more so now because almost all my customers want a frame mounted handspring ( Ruger style)! That means the whole back side of the hand is a bearing surface. It has to be "hardened" so the "hardened" pushrod (long plunger) won't gouge or gall the hand. During hand "fitting" it is still soft so during test fitting you can see this happening. After fitting, the hand is "cleaned up" (resurfaced) , "hardened", de-scaled, dressed and finally polished! I'm sure denster sees no point in all this and it's probably wasted time but hey, it's my time and it results in a setup that has a main role in the overall" feel" and "life" of the revolver's tuning!! Guys, if it wasn't a necessary step in my work, I wouldn't be doing it!!! Heaven knows, I need the time if I can find it!!! (Just look at some of the post in this very forum!!!!!!). But as I said, I don't do "average" so if it takes time, then, it takes time!! By the way, my revolvers have won Ala., GA, and NC state championships, . . . (that's just a selfish plug for me!!!)!!
So, just getting back to the "hardness" issue , the hardness test for a 1st gen. Colt SAA is RC 48-52 equivalent; 2nd gen. RC- 45 equivalent; 3rd gen. RC 47-50 equivalent. Uberti hands (early) RC 25-30 equivalent intermediate/late RC 28-32 equivalent, Armi San Marco hands RC 28-32 equivalent, Pietta ranged from RC 20-26 equivalent.(sourced from Jerry Kuhnhausen's book "The Colt Single Action Revolvers A Shop Manual, Vol's. 1&2)
The manufacturing of revolvers demands certain "minimums" and I would assume (as big an audience as both Uberti and Pietta have) these minimums include steels suitable for the job intended. I treat these parts as they should be treated whether the steels are correct or not (I ain't gonna make new parts folks!!), which means they are taken to a soft state, "fixed", and re- heat treated. This includes the screws supplied with the revolver, which respond accordingly . . . (a hard screw is a much better bearing surface than a soft screw (and yes, the steels used respond to heat treating!!)
So far, all of the heat treating of parts done during tuning result in the desired result (as instructed (meaning by those that actually know)) and see absolutely no reason to take any advice from an unknown source!!!
Mike
Not to mention, anybody that has ever worked on Rugers (not a "spring changer") knows, if you even attempt to stretch an " as is ” hand (pawl), you can't. It WILL break!! You can soften it, stretch it, re-harden it, and reinstall it in a championship earning revolver!!! (I know this for a fact!!!) (and as far as that goes, Pietta's as well!!)