I'm doing the rifled barrel now, if anyone is interested I can post some pics of the touch hole process I used in a day or two.
Please, do. I've like to see it.
Best regards
Rolf
Rolf, here are some photos and details of the process I used for the touch hole and liner -
First step was to locate the desired center of the touch hole and to punch a mark. Then I set up the barrel in my drill press (I left the barrel in the vice throughout the entire process, from the first hole drilled to chamfering the liner hole after threading) and used a small center drill to start a hole. I used progressively larger drills until I had a 5/32" hole to fit the pilot on my home made counterbore. The counterbore was made from O1 tool steel and the diameter is 3/8". I turned the counterbore by hand in my drill press so I could sneak up on the desired depth.
Next I drilled the center hole progressively larger until I reached a #3 drill size, the tap drill for a 1/4"-28 tpi hole. I switched to a 1/4-28 tap and threaded the hole turning the drill chuck by hand. The last step was to chamfer the hole for the shoulder on the vent hole liner. I fit the vent liner in the barrel several times with the barrel still in the vice, then chamfered a little deeper until the liner seated to full depth, then removed the barrel.
Next I cut the vent liner to proper length for the barrel wall and used a diamond bur to polish and shape the cone inside the vent liner. Then I cleaned the threads on the barrel and liner with acetone, and put a drop of blue Locktite threadlock on both sets of threads, and tightened the vent liner quite snug.
I then cut two small sections from a brad nail and peened them into the screw slots to fill them, and peened the edges of the vent hole liner tight.
Next put one leg of a compass in the hole and lightly scribed some concentric circles on the barrel and marked some straight centerlines, all to help properly locate the hole in the vent after the gold was in place. You want to be precise with this! I undercut around the bored hole with a graver, then I sawed out a gold disc to fit the hole and annealed it.
Next I used flat round punches of various sizes to peen the disk solidly in place. I also used a domed punch when I wanted to move metal in a specific direction.
When satisfied the disc was well seated I filed the disc smooth, then I used my compass and scribed lines to locate the hole and carefully center punched a mark. I used a tiny drill in a pin vice to drill the hole through the gold. Success!
I used progressively larger drills until I got to 1/16" to match the hole in the touch hole liner. I shined a flashlight down the barrel to check the hole and it looks perfectly centered.
I filed the gold to just proud of the barrel surface, and will file it flush when the gold band is installed so I can file them at the same time.
Hope this is clear enough, if you have questions please ask!
Curtis
