Another question. Stainless steel, 300 series at least, does not tranfer heat as well (By a LONG shot!) as carbon steel. I know that handguns are commonly made of 17-4 or 416, but I'm wondering if you could do that with a SS gun?
Also, I saw that the heat color on the barrel in part 3 was light brown (Straw), That shouldn't effect the longevity of the recoil spring, but getting closer to that failure mode. Steels lose strength as they get hotter too, I wonder at what temp one would expect to see blown barrels, or cookoffs!