Flash Hole Liner, often called a vent, vent liner, or touch-hole liner.
Threaded M8-1.25, made in the USA, stainless steel, slotted for easy removal. This liner is used on Davide Pedersoli Frontier longrifles, or Cabela's Blue Ridge longrifles.
Concave inside, this vent liner brings the main powder charge very close to the incandescent heat of the priming flash. Position the vent on the center of the pan, slightly above the pan to frizzen joint, sometimes called the "sunset" position. Covered by the frizzen when closed, the hole is a window centered on the heat of your priming flash, for instant ignition, without the whoosh-bang delay, seen in many flint guns.
Only the better quality London made guns were factory fitted with vent liners, but nearly all flint guns were later fitted with vent liners, after the vent hole in the barrel became worn from flash erosion, corrosion, or the aggressive use of a vent pick.
This metric size fits most Davide Pedersoli pistols or rifles.
Dab a tiny amount of our #BC-CTL
Birchwood Casey's Choke Tube Lube on the threads, to prevent this vent liner from becoming stuck, after each cleaning.