Breeching barrel blanks

[bioprof]

I see that there are some rather inexpensive barrel blanks available on Numrich's gun parts web site. Is there any way to drill them out and tap them for a breech plug without a mill or a metal lathe? Could you just use a drill press with a tap drill and then taper the breech plug to get a snug fit, or would it be better to use a mill bit to get a square shoulder to fit the breech plug against? Anyone tried this with just a drill press???

 

[John Taylor]

The old timers did it without a lathe or mill. I think they did not butt the plug against a shoulder, just cut the threads to what ever bore size they had to work with.The way some of the originals were done we would call unsafe today.

 

[Bubba45]

In one of my gunsmithing books is shown setting the barrel up in a drill press ,drilling and tapping for a breech plug.I would suggest starting with a taper tap and regrinding a bottom tap so it would put threads all the way to the bottom of the hole so the plug butts against bore.

 

[44-henry]

Though a lot of them might have been done without the aide of a lathe, you can bet the gunsmiths that did this work had some other assistance and didn't just wing it. I've seen original breeching tools that used pilots that entered the bore to keep the drill and tap inline when performing these operations. With this kind of setup the job could have been done with the barrel in a vise and the tool would have been turned with a brace. I would imagine that this type of tool was used quite frequently.

 

[ehoff]

Get ahold of a copy of R.H. McCrory's book "The Modern Kentucky Rifle" he shows how to drill and tap a barrel with a hand drill, including grinding a bit to get a flat bottom.

 

[George Holton]

This is a fine book, I have done it his way many times Bob

 

[rich pierce]

Those barrels are chrome moly 4140 and real tough to machine.

 

[George Holton]

OH! :surrender:

 

[Jim-Iowa]

Can't say I have seen one, but one should be able to buy or make reamer that could be driven by a brace to cut and make the sholder. Just as they hand cut a chamber in a centerfire barrel? Then as was said above a tap and plug tap could cut threads.

 

[John Taylor]

A reamer like you are talking about could be made from an old tap but it would require the use of a lathe and tool post grinder to keep it true. Also it would mess up the rifling near the breach plug because of the pilot. Start by grinding all the threads off and then grind about half the tap down to bore diameter for the pilot. Sharpen the leading edge of the large diameter and then feed it into the barrel while turning. It will cut like an end mill and the pilot will keep it centered to the bore. It would be a good idea to use a pilot on the tap also to get it started strait and a separate tap to bottom the threads.
This would not be an easy job on a CM barrel but a 12L14 barrel will cut OK.

 

[bioprof]

I think I'll leave it up to the professionals. Besides, for most of them, you don't know who made the barrel or the quality.

 

[Runner]

Rich, my little machine will only pass 3/4ths thru the head. I can bore the hole for you if the barrel is small enough. Tapping that steel might be a chore. Cutting inside threads is a pain, but I believe we could start them with the little lathe and then finish them with a tap. Tapping the way JT shows in the Brass underhammer thread is possible on the little lathe and the little drill press.
John, if you used a bronze bushing that was a tight fit to the rifling and cut the lead pilot to fit the hole in the bushing instead of the barrel, you should not damage the rifling doing it your way.

 

[John Taylor]

Runner, your right about the bushing, I had a senior moment. It's tough getting old, of all the things I have lost I miss my mind the most.

 

[44-henry]

You make a very good point when you mention the quality of the barrels. With all of the work that goes into building a rifle or pistol I can't really see any good reason to try and save $50 bucks or so on an unknown quality barrel. Considering the amount of labor that historically went into barrel construction, today's barrels are bargains in comparison.

 

[Runner]

I have already seen enough of your set-ups to know that you would have done it that way once you thought it thru, even if you did not mention that option in conversation. Believe me, I am enjoying everything you post. I don't have a machine tool background, but I have started collecting toys over the years. I am barely a beginner at using them! I have a lathe that I could turn a 44 inch barrel between centers, but no training on setup and usage. I am considering a community college course to help me along.