I had always figured that Cyanide, when done right would have to give a surface hardness similar to bone charcoal. If not then the steel used would have needed to be changed and for sure the malleable iron guns never would have been colored and harden enough for use by cyanide process.
What I wondered was why the change from bone charcoal to cyanide? Handling the materials and disposal, which was not a major thought 75 years ago, has to be more complex with cyanide based materials. Bone charcoal process were well known, with "secrets" being passed down from one generation to the next. So it must have been a cost cutting measure and perhaps more predictable color outcomes. Marginal improvement in hardness would not have caused all the makers to go down this route. In fact I suspect they would have accepted a reduction in surface hardness as long as they thought it to be below critical level.
Profit margins were razor thin on doubles so cost reduction must have been the driving force. What was the cost difference, fifty cent per gun? Maybe it was once one changed they all had to "keep up with the Jones" or be perceived as using the old system when a better, newer one, more modern one, was in use by their competitors.
Beauty is in the eye of the beholder but I always found the Cyanide colors to be too harsh. Perhaps there are ways to tone them down but time and "sunshine" don't seem to affect them as much as some bone colors. Maybe it's just the fact that they are newer. The water color colors of some of the Remington 1894s are as pretty as any painting I have ever seen.
