Drew,
Hope your mission trip to Guatemala was productive and rewarding!
This information from Adam is very interesting! I question the carbon content stated in your text. 0.01 carbon content would be virtually nil. Is it possible that the decimal point is off one place? Maybe the correct number should be 0.1?
Still, I am surprised that the average carbon content is so low as 0.1. Though, I would not argue with the analysis. My SWAG estimate would have been 0.3 to 0.4.
From what I have read in old metallurgical books, they were quite adept at controlling the carbon content in steel at the time damascus barrels were made. 0.5 to 0.6 carbon content is sufficient for making springs and cutting tools. They were aware of the difficulties of heat treating hypereutectoid steels, so typically avoided making steel with more than 0.8 carbon content. Given this information, I have assumed that the carbon content of the "steel" element used in gun barrels to be around 0.6 to 0.8 carbon content.
Greener wrote that the steel to iron ratios were typically at least a 50/50 mix in English made barrels. And usually, the steel percentage was higher than the iron. Assuming a 50/50 mix of steel and iron, and knowing that carbon migration would happen at the elevated temperatures of forging, I would have made the guess that the average carbon content of gun barrel steel would be in the 0.3 to 0.4 range. This however, may only apply to English barrels. Without information on Belgian barrel steel, it may be possible that the Belgian steel could have been lower in carbon content. It would be interesting to see a chemical analysis on an English barrel, to see if the average carbon content is higher.
