I love this forum.

It is unlikely that heating to 750F would anneal heat-treated steel. For example -- 4140 (chrome moly carbon steel) is used very commonly in the manufacture of firearms for receivers, bolts, barrels, and other high-stress parts. It does not anneal completely until heated to 1600 F. Hardness treatment requires quenching from 1550 F. Tempering requires re-heating to a range of 400 F - 1200 F. See Alloy Steel 4140 - All Metals & Forge [Again, normally you consult material data sheets for the steel you are using, and those tell you things like, how hot you should heat the steel for tempering in order to achieve a given hardness result (e.g. 40 Rockwell).] You could heat the steel to 800 F and leave it there for a weae and while it might acquire more temper (assuming it had not previously been heated to 800 F) it is not going to anneal.

BTW, this begs a related question....which is, what kind of steel did (and does) S&W use in its revolvers? I think the stainless is mostly 316 (not sure) but I have never been able to find out. If you could find out what types of steel were used in a particular revolver, then you could consult the data sheeets for those steels and assure yourself that heating to 750 or 800 F was not going to materially change the hardness of the steel. I checked the previously mentioned sources (Jenks' "1857-1945" and Parsons "Early Single Actions") and couldn't find any reference to the type of steel used (although there were a couple references to steel suppliers). I also searched this forum and couldn't find anything. Anyone have any insights?

Also -- what could be used as a modern analog for Carbonia oil?