Hmmm....so, any mfg producing properly heat-treated revolvers? Or do we accept that BP revolvers will just wear out after a bit?
Well, I don't want to make blanket statements based on anecdotal evidence, but I currently own:
Richmond Carbine James River Armory (Armisport?). Had sear spring go soft. I took it out, heated it in a propane flame in a metal cap can full of leather pieces for an hour, then quenched it in transmission fluid, polished it, heated it to straw/blue and quenched it again. Works fine now.
Euroarms P53. Sear nose mushroomed then broke off. Ground a new nose and carburized and heat-treated as above.
Cheap-o brass-framed "1851 Navy" CVA .44 revolvers. The ends of the hands mushroomed. Filed and heat treated as above to fix.
Pedersoli P58. Tumbler stirrup arm was too small for the hole in it and broke. Replaced with Lodgewood machined replacements.
Pietta 1858, 1860. Haven't shot enough to have any problems yet.
How does this situation compare to orig production techniques in the mid-1800s? Is lack of heat-treating a more "authentic" reproduction?
Repros are nothing like the originals. I bought an original Enfield (I have since sold it).
Check out this photo that clearly shows the nose of the sear and the notches on the tumbler:
They are still as crisp as if they were made yesterday.
It's lock internals were as good as new in spite of being 150 years old and a rough Indian-service gun. For starters, these firearms were manufactured as military equipment and expected to see hard service.
Also, most, if not all of the original steel parts were machined or worked from solid stock. Many of the components in reproductions are castings, which do not take heat treating as well as machined parts.
Most original pieces were hand-fitted with close attention to detail. Workers were "mulcted" - fined - for producing sub-standard pieces. So if you screwed up a part it came out of your pay.
There was junk produced back in the day, too (gas pipe / trade guns), but generally speaking the originals were very well manufactured items. Probably much better than we have today.