Re- Breeching a barrel

[PIKELAKE]

There was a post several weeks back about the number of threads a breech plug should have to be considered safe and I have a question. I have a rifle I built many years ago " before I got religion" and pulled the barrel and plug to take a look. It seems that my attempt back then to get a perfect fit between the plug and barrel I came up with a plug with only about five full threads. My question is this. There is enough room between the barrel end and the touch hole to cut at least three more threads maybe more. I know I would have to replace the plug or I could even start over with a new barrel for that matter. Is it possible to cut about three more threads and what would likely be involved? It seems that the barrel would have to be drilled out a tad more " without damageing the existing threads" and then threaded to create a new shoulder. What do think? Too much trouble? Wall hanger? It is a nice rifle and I want it to be safe after I'm long gone. The barrel is a 54 cal., with a 3/4-16 thread plug if that matters. Thanks for any help..JZ  P.S I have never fired this rifle and it is about thirty years old.??

[Acer Saccharum]

You can certainly thread it deeper.

I would suggest using a lathe to do the work in, to prevent from chewing the hole larger.

Make a smooth plug that just fits snugly in the existing threaded hole. Set the barrel in a four jaw, and indicate on that plug to get it to run true. Then you can drill out a little deeper, square up the shoulder with a boring bar, and tap again.

[PIKELAKE]

Thanks Acer for an answer. Maybe I'll give it a try. All I have to do is find a good lathe man. I have a wood lathe but no metal lathe or the know how. Thanks again..... JZ

[D. Taylor Sapergia]

How long is the journal on your breech plug now?  Is it threaded for it's full length?  Does it bottom on the end of the hole?
If the answer is 1/2" or longer, yes and yes, I would not do anything to it.

[PIKELAKE]

Taylor, as it stands right now, this rifle is breech-ed perfectly. The plug mates with the shoulder of the breech perfect. My attempt to accomplish this and index the plug with the barrel flat that was appropriate caused me  to "take a little off the barrel and then a little off the plug". First thing you know I'm short the 8 threads that were mentioned as being considered safe. The plus for me, if there is one, is that there is still enough barrel to cut some threads and move the shoulder forward behind the touch hole. A new plug would then need to be installed with much more care. The current plug has a little more than 5 full threads and is 7/16's long. I'm darned near tempted to really load her up and proof it,safely of coarse. I have learned a lot since I built this rifle and it doesn't hurt to go back and check things out on the early stuff made. Hope all this makes sense, thanks again... JZ     Still can' figure why I never shot this rifle; Divine Providence?

[Don Tripp]

What about going to a 7/8-14 plug, drilling the breach hole just a little deeper and re-threading. A drill press would probably work. Who made the barrel and what are the dimensions?

[PIKELAKE]

Hey Mr. Tripp, neighbor, your approach sounds reasonable to me. I can't remmember who made the barrel, but it is one and 1/16 inches wide at the breech. This afternoon I talked with a local gunsmith with a lathe and experience and he claimed that he should be able to cut some more threads without changing the current size of the plug. I'll get a new plug and let him have at it. I will be at peace knowing that it will be safer than it is now I hope. I will even shoot it. Thanks to all for the suggestions,.....JZ

[Don Tripp]

Neighbor indeed. I spent a lot of time in Adrian when I was a kid. My Grandfather sold Oliver Tractors in that area, in Deerfield