I read in "A Forgotten Heritage" about a technique I had never heard of before. The author stated that the breech of the barrel was heated and a plug that already been threaded by hand file was inserted in the end. The smith then hammered the barrel around the plug until he got the fit he needed. I had never heard of this before so I went to the Dillon book to look it up. The only thing that I could find there said that the breech pin was installed with hand tools, which neither confirms nor contradicts. I can see where a tap could be a rare commodity in an isolated gunshop, and can't ever remember seeing anything other than a screw plate listed in any inventories. So what do you think guys ? Maybe ? Maybe not ?