After everyone is scared to death about adding length to a wrought iron barrels. Let me state my case. Forget adding anything to the breech end. Sometimes I might do a new build with a WR barrel and all the rest WR. 3" or 4" added to the muzzle end is very safe procedure. It has nothing to do with welding. It has to do with machine work and a short piece of old barrel. The barrel is proof tested to the the extreme. If you want to know more mail-me. I'm talking about a shooting rifle here.
The question would be:
"Why bother?"
While I can see adding to the barrel by threading ect and this being little different tha a patent breech and there have been barrels repaired at the breech in a similar manner.
I can see stretching or repairing a barrel to restore a rifle to its original length.
I don't see the point of using old barrels for actual shooting.
While I have issues with the contour of many modern swamp contours this is not enough to have me using a old iron barrel that I really have no idea of the quality of material.
I had a phone discussion with a fellow poster here who makes barrels, rifles and also does restoration work.
The subject of inclusions came up and we both agreed that the old barrels have serious problems with inclusions.
"Frontier Colonial Guns" has sectioned barrels from trade guns of various types. Its scary.
Reading W Greener from 1832 he complains of the poor quality of the iron export barrels. He points out the guns bursting in service in England prove that the proof method is faulty and then goes on to use what is now laughable ideas for improving the proof house. Not understanding the failures were a result of the metallurgy of time and that its impossible to prove a barrel is safe by its surviving proof.
Inclusions are a prime cause of barrel failures and were something that a prospective gun buyer was warned about "back in the day". "Greys" in damascus barrels were a problem. Inclusions is gun parts even to the late 1860s is really scary. Repair/rebuilt work on Civil War era guns and even later is made far more difficult by the poor quality of the material.
Even the steel barrels of the late 19th century have inclusions, that in their old age, show alarmingly in the bore and on the exterior. This really did not disappear until the widespread us a smokeless bringing about the use of better steels and closer attention the making and where necessary the forging and heat treating of parts. I would cite the "low number" 1903 Springfields as a problem of this sort that involved over a million US service rifles that are now considered to be unsafe and specifically are banned from most if not all modern day service rifle competitions.
Are
all old barrels/firearms unsafe or weak? Of course not. But there is no way to really determine a good barrel from a bad one. If its rebored and seems to be good with no obvious hard spots etc it may very well be as good as a modern barrel.
But there simply is no way to really determine this other than some laboratory that specializes in metallurgy and even then the determination may require destroying parts of the barrel.
So, in general, I would decline to resurrect an old ML barrel unless it was lined with a modern liner.
I don't really like shooting pre-Civil War or even 1880s barrels but I have with a knowledge that its a risk. A chance to shoot an original Hawken rifle, for example is not something I wanted to let pass by. I have shot other original barrels including an original 1814 "Common Rifle". But I understand the risks and in some cases choose to accept them. In most cases I decline.
From a professional standpoint I tell anyone that old barrels are not safe and if they shoot them they do so at their own risk.
Dan