ronlaughlin

There is one breech plug commonly available, that really requires no modification. That be the Omega breech plug. It will work just fine the way it came from the factory.

If one wishes to modify this plug, the first step should probably be to increase the size of the flame channel. The factory flame channel is 1/8". One can easily increase the diameter by using a 9/64" drill in a drill motor. The drill will naturally follow the existing hole, and one can easily tell when the drill has hit the flash hole. Once the flash hole is hit, one wants to quit, because the flash hole is only about 1/8" long, and one could destroy it without a lot of effort. Then one should install a 5/32" drill in the drill motor and drill the flame channel to 5/32". This larger flame channel will allow more shots between cleaning.

After hundreds of shots, the flash hole will be much larger than the 0.029" it was when new. At that time, one may want to install a vent liner, which will replace the flash hole with a new smaller size, and allow the breech plug to be used for hundreds more shots.

Really, the last modification one need do to the plug, is the one done here in this thread.



The first thing i does to the plug is to drill out the primer pocket with a letter Q drill. Then the threads are cut with a good tap. The taps used here i purchased on eBay, and are from Yugoslavia. The local machine shop sells me taps from Bosnia, and i think that is what Yugoslavia became. First a regular 3/8 X 24 tap was used, then a bottom tap was used to finish the threads.

The grade 8 bolt used was cut with a porta-band saw. It is near impossible to cut a grade 8 bolt with a hack saw. The head of the bolt was cut off so the bolt could be mounted in a 3/8 collet on the lathe. A 5/32" hole was drilled though the bolt. A 3/8 drill with the same 135 degree angle as the letter Q drill was mounted on the lathe in the collet, and used as a guide to set the lathe cutter. The cutter then was used to cut the end of the bolt at the same angle as the bottom of the hole made in the breech plug by the Q drill. This allows for a nice tight fit between the bolt and plug when they are married.

Then 2 flats were ground into the end of the bolt so it could be turned with a wrench. Red loctite was put on the end of the bolt, and on the threads, and the bolt was tightened into the breech plug.



After a rest, the breech plug was installed in a 11/16" collet in a collet holder, clamped on the work bench, and the bolt was cut off to near finish length with the porta-band. Then the breech plug was mounted in a collet on the lathe, and the threads were turned off the 'neck'. At this time the final length of the 'neck' was cut on the lath.

Then a letter C drill was used to drill a pocket for the primer. The finish depth of the primer pocket was arrived at gradually by using another letter C drill that has been ground nearly flat.



When the length of the plug and primer together was very nearly the sought after length to get a slight crush of the primer in my rifle, the pocket was polished with fine sand paper. The last few thousandths of inch were cut off the muzzle end of the plug instead of the bottom of the primer pocket, cuz it is easier for me to get the desired length that way.