ed's descriptions show a considerable lack of understanding of steel metalurgy.
point - case hardening has almost nothing to do with strength and a lot to do with preventing wear. Bone charcoal CC'ed receivers will be low carbon steel. If a receiver is not adequately strong before hardening, it will not be strong enough after hardening. The engraving on a soft receiver will wear away quickly compared to the engraving on a cased receiver.
point - the colors and the hard case are fundamentally independent of each other. Steel can be case hardened without colors and it can be colored without hardening.
point - the colors are aesthetic, not structural. Note that guns continue to function as designed long after the CC is worn away. It is well known how to produce generic case coloring. However, the accurate reproduction of CC specific to a maker, trade, time period, etc. is very difficult.
DDA
