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The cyanide salt bath is upward of 1700 degrees fahrenheit and it produces a true case. However, it may be that the process shown is something other. Too bad they couldn't elaborate.
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It is different, although before seeing a youtube thing about CCH I'd have thought the temperatures you mentioned are closer than what I posted (1400-then down to 1100, then quench)
They pack the parts in special pots with bone and leather char, then bring that up to temperature and drop the contents into water with an air outlet at the bottom so it's bubbling. I've read that really fine case hardening brings the surface to a very high hardness while internally there is some conventional hardening for added strength, but mostly case hardening is done to 8620 and it is close to mild steel, 20 points carbon.
BTW, grip screws in original 1911's were case hardened to 60 RC, I tried to file one once, it ruined the file. Since reading the Kuhnhausen books I see that no one makes a 1911 the way they used to, and no, they are not better as far as heat treating goes IMO.