Bob, I'm wondering... do you think that 12L14 is any more dangerous than the wrought iron 18th century makers used to make so many of the barrels in the original firearms we admire and try to so hard to reproduce?
I'm not Bob but the letters below should be required reading for anyone interested in this subject.
I am not a metallurgist. The following are things I have learned from various sources over the past 30+ years of interest in the subject. You may consider it opinion if you like.
"Best" iron actually makes good ML barrels. But "best" is a key word here.
Look at the inclusions (called "grays" in the trade from my reading) found in barrels pictured in "Colonial Frontier Guns" By Hamilton.
In the 1830s W. Greener was complaining of the poor quality export barrels being made.
Making barrels from old wagon tires, for example, is probably not using "best iron" as Springfield did for rifle musket barrels during the Civil War.
Inclusions were a major problem with iron that was not properly processed to remove them. But like making high quality steel today the process was expensive.... English "damascus" and "twist" SHOULD be very good but the care in making the steel and in the welding is critical. Good damascus barrels are often proved for nitro shotgun use. English machine made damascus being equal to the late 19th century "Whitworth" steel etc.
Modern steels with high levels of lead, sulfur and phosphorous have problems with inclusions too. Free machining steels like leaded screw stock are relatively heavily leaded, and resulfurized and have high levels of phosphorous. Then they are cold rolled to make them brittle, this increases the tensile numbers but does NOT make the steel stronger when used as a gun barrel and invariably REDUCES its tolerance for internal pressure and shock loading and can cause brittle fracture with fragmentation. Nor is the level of inclusions controlled in any way or even tested. So some bars are relatively "good" and others really scary. Its usually impossible to tell one from the other by eyeball. A piece of steel can be riddled with inclusions and still
look just like a piece of steel that is properly heat treated and certified for very low levels of inclusions as the higher grade steels are. Think "best iron" vs wagon tire grade iron.
This letter was sent to John Baird when he was publishing the "Buckskin Report" and the text was published in the magazine.
And these from the same time frame.
This one needs careful reading as well.
Dan
