ronlaughlin

Hunting season ended for me yesterday; this morning i modified 3 more Accura breech plugs.







It didn't take me very long even though i am not a machinist. Here is how an old carpenter works these breech plugs.

First thing is to measure the diameter of the Accura breech plug.



Then clamp a block of wood to the drill press, and drill a 5/8" hole in the block with a forstner drill, which leaves a flat bottom hole.







Then one needs a way to keep the breech plug from spinning in the hole whilst being drilled and/or tapped. This can be done by using a 'set' screw on a 'flat' of the hex end of the breech plug.








Then a 3/8" drill is installed, and the belts of the press are set for the slowest possible speed, and then used to drill the 'powder pocket' in the breech plug. Oil is used to keep the drill cool, and help it cut.









Next a 25/64" drill is installed and used to slightly enlarge the pocket and to form more of a 'seat' for the vent liner. It is possible and reasonable to eliminate the 3/8" drill and just use the 25/64" drill.





Now it is time to use a counter sink to accurately form the 'seat' for the vent liner. Oil is used so the counter sink can be used again.





Here are pictures of the process to drill out the flame channel so it can be tapped to receive the threads of the vent liner. First a 9/64" drill is used, then a #21 drill, along with plenty of oil.








Now the plug is ready to tap. The drill press can be used to hold and align the tap if the belts are disconnected. Then the tap is turned by hand. Oil is used to assist the cutting, and the tap is turned about 8 times.
















The finished plug