How Does a Touch Hole Liner Improve Reliability?

[smoothshooter]

In answer to your question, they don't necessarily ! Keep in mind flash hole liners for the average flint gun is a modern notion as virtually all of the originals we settled America with never started life with flash hole liners. They were most often employed for repairs when flash holes became eroded from hard usage or cleaning neglect.

Your statement is true.
However, some barrels left their maker with an enlargement done from the inside to shorten ignition time.
I have seen one picture and 2 very detailed drawings from the mid to late 1700’s showing the tool this operation was done with. A very complicated tool for the times.
I think the inside-coned vent hole feature started out as more of a British thing done on some higher quality guns.

 

[smoothshooter]

Your statement is true.
However, some barrels left their maker with an enlargement done from the inside to shorten ignition time.
I have seen one picture and 2 very detailed drawings from the mid to late 1700’s showing the tool this operation was done with. A very complicated tool for the times.
I think the inside-coned vent hole feature started out as more of a British thing done on some higher quality guns.

 

[M. De Land]

Your statement is true.
However, some barrels left their maker with an enlargement done from the inside to shorten ignition time.
I have seen one picture and 2 very detailed drawings from the mid to late 1700’s showing the tool this operation was done with. A very complicated tool for the times.
I think the inside-coned vent hole feature started out as more of a British thing done on some higher quality guns.

Yeah, I've seen the tool as well but never known for sure if it was historic or of modern thinking although very logical. The trouble with doing it without a hardened liner is how it would respond to less material to erode in the barrel wall from heat and pressure.
It certainly was known about as high end European arms are often lined with platinum and gold rivet/linings. The interior coning tool makes me wonder if this wasn't really made for the gold and platinum rivet lining installations instead of coning flash holes . The interior coning certainly does encourage main charge pressure escapement and probably faster hole erosion.