BarrelI was given a set of plans for the barrel from a friend of mine. He had measured the diameter of an original barrel in 10mm increments along the barrel.
I ordered three barrel blanks from FCI(C. Burton), smooth bore, gauge 16(one spare blank in case I mess up one), threaded 7/8-14 for the breech plug. I asked him to thread the blanks because they wouldn't fit through the hole in my lathes headstock. The first I did was make a "dog" so I could turn the blanks between centers. The dog is made from 40mm round stock. One end is center drilled, the other end is turn down and threaded 7/8-14. A 10mm bolt is threaded in the rear end of the dog to engage the headstock of the lathe.
The threaded end of the dog is 1 inch long. The barrel blanks are threaded 1/2 inch deep. This makes a gap that allows the blank to be turned all the way to the end of the breech. The flats on the dog make it easy to hold in a vice for mounting and removal of the barrel blank.
The barrel is turned down stepwise, following the measurements in plan. The steps are quickly removed with a coarse double cut half round file with lathe spinning. Using a single cut mill file for this will take forever. The coarse file marks are removed by draw filing the barrel while it is still mounted in the lathe(not spinning). Polishing is done with 280 grit emery cloth with the lathe spinning. Took me about 5 hours to do a barrel from start to finish.
Breech plugs.I started by making a 7/8-14 threaded rod on the lathe from a rusty piece of 40 mm axel I had in the scrap pile (quicker and cheaper than trying to get threaded rod from the USA with todays exchange rate.)
With out the tang interfering, getting a tight fit against the breech shoulder is quick and easy.
Mill the top and sides of the plug flat. Superglue the tang blank on. Drill and tap for two M3 screws. The screws will hold the tang in place during welding.
Remove the screws, heat to 170 Celsius, dismantle, clean up the glue and file bevels along the welding area. The none beveled rear portion will be cut away after welding. Its function is to keep the tang level and straight during welding.
Welding done with a MiG welder. 260 amp gave full penetration and fusion. The threads were coverd With masking tape to keep them clean from Welding splatter. The weld is almost invisible after clean up. The front screw head is cut off and the rest of the screw used to pean the hole shut. The rear hole is left open, because the hole for the tang screw will be drilled there.
Finished barrels and a blank.
The 1772 pistol Project is going to be stored in mothballs for a while. Need to find a gun I can use to copy the trigger guard, buttcap, pipes and Stock.
Best regards
Rolf
