Hi James and Jim,
Thanks for chiming in. Tim, it was a different post. We always have to be careful when discussing British work because it changed over time. I believe it is always important to provide a time period just as we do for long rifles. For example, the high end silver mounted fowler by Heylin that I bought from James Rogers shows excellent workmanship but much the lock mortise is rather roughly inlet. Not the edges but the guts. It is well done but nothing compared with the work you see on early 19th century British guns. My 1820s fowler by Fields is a good quality gun but nothing like the Heylin, yet the inletting puts the Heylin to shame. I don't think you could do better quality work with computer assisted machinery and this was a fairly ordinary gun. Procedures and standards changed over time. I suspect if final seating parts by burning was used much, it was during the 19th century when there seemed to be a demand or standard for supremely precise fitting of parts even in places that never show. There is another aspect to this that you all might consider. I am speculating here and from a broader view of British trades but hear me out. In America, there was always a shortage of highly skilled labor. That was partly due to the British discouragement of value added industries in colonial America. We were to provide the raw materials to Britain, which they manufactured into goods that were then sold back to us. This was part of the mercantilist system that Adam Smith criticized so much in "Wealth of Nations". We took to machinery much faster than the British despite many of the pioneers of powered machinery being British. It was because we had to supplement our dirth of skilled hand labor. In Britain, particularly in the gun trade, there was a wealth of skill and talent doing hand fitting and fabricating, and they were very antagonistic to any mechanization in the industry. The gun industry in Birmingham alone was the largest in the world. The vast numbers of British gun workers could do by hand what machines in America did by automation. The extreme division of labor aided that result. I believe part of the effort for precision in hand work observed in British guns even of middling quality was an effort to show the workforce could compete with the machines. That battle continued right up to our Civil War when Birmingham makers combining some machine manufacturing with a lot of hand labor made fortunes supplying the north and south. Yes, they adopted machining for some of the tasks but nothing like the Americans. So in conclusion, it might not be surprising to observe British gun makers using methods promoting precision at little cost of labor, like burning in, during the 19th century but not during earlier periods.
dave