How to tap the breech for a plug?

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Janissary

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I searched but couldn't find info on what type of tap is needed for the breech. Is any ordinary quality hand tap good enough for the job, or is a stronger tool required? I suppose a bottoming tap is necessary, but should I also have a taper tap to start the threads?

I imagine it may depend on the type of barrel steel. After reading prior threads on this forum and considering the many different opinions, I'm considering making a barrel out of DOM tubing, specifically "ASTM A513 Type 5, 1020/1026 mechanical grade" steel, so that's what I'm curious about. If I decide to pay up for better barrel steel then I may as well buy a pre-threaded barrel from TOTW.

I don't have experience tapping save for doing it in some aluminum parts many years ago.
 

Vaino

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I'vr tapped breeches in my drill press w/ a special setup. Bought 2 tapered taps and ground one into a flat bottoming tap which is also used on new bbls to "clean up" the threads close to the shoulder......Fred
 

TFoley

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Through-headstock machinists lathe and extended steady - >$10,000.

Or

Quill drive precision pillar drill and suitable precision vice/vise and set-up blocks > $3500.

Or

Buy the barrel with a breech plug installed - ~$400 or so.

You choose. :)
 
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I got my Southbend 10" for $600. It came with two chucks, collets and drawbar, steady rest, spider, and other goodies. The hole in the spindle is 1.4". It is a WW2 Navy contract machine. They are out there. The older generation that likes this stuff is passing it on. You do not need CNC or a modern machine. Mine was used by a working gunsmith for 50 years. You don't need to spend lots of money.
I bore breech plug thread on it. Once they are super close I finish with a bottoming tap guided by the tailstock.
 

Red Owl

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For most of us this is a hobby and one problem with that is that it can get expensive buying the proper tools for a job you may only do one time. As a result a lot of us work up a "gizmo" to do the job but these gizmos usually require a lot of time to make, use, etc. I'd say this may be one job worth farming out.
IS THAT PC? Actually, yes. Colt's first revolving weapon was a rifle and I think he had the barrels made by J.J. Henry of PA. A lot of the early makers had locks, etc. farmed out to subcontractors. The same thing was done with knives.
 
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I guess it depends on how deep one wants to go down the rabbit hole. I have a couple of old lathes and and older mill. I use them constantly. I make most of my accessories and guns I shoot. The old lathe and mill are defiantly multi-taskers.

There is nothing wrong with assembling kits or doing little refinish and remodel jobs. IF you want to go deeper then some tools are required. If you buy old stuff it is pretty cheap. Some take the challenge to use and make period correct hand tools, a tumbler mill for instance. That is a wonderful academic pursuit. The depth of knowledge needed is greater than using machine tools. Gizmos, I am not a fan either. I have observed that the resulting finished guns made that way are often not up to my expectations for quality. For me and how I like to do things the old machine tools are excellent.
 
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They used taps. Some of the taps look pretty crude by modern standards. The barrel steel was very soft and ductile by modern standards. The plug was done with dies. Since the barrel steel was so easy to work taps that formed instead of cut worked.

Those tools would not work well with modern steel.

 
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Well, I'm an outlier on this topic being that I did drill and tap a cut off for a breech plug. It was done with a hand drill and hand driven tap. It worked out ok. Probably because I didn't know any better. :doh:

I started with an undersized bit and went slow allowing the bore to be my guide. Gradually went up with increasing drill size until I got to the minimum recommended size for the tap. Got started with a through (tapered) tap and finish with a bottoming tap. I actually ground the through tap down to be a bottoming tap but if I do it again I'll just go with a bottoming tap.

I don't recommended doing this and don't consider this a guide to DIY! Like I said. I didn't know any better and just cause it worked don't make it a good idea. :oops:
 

TFoley

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They used taps. Some of the taps look pretty crude by modern standards. The barrel steel was very soft and ductile by modern standards. The plug was done with dies. Since the barrel steel was so easy to work taps that formed instead of cut worked.

Those tools would not work well with modern steel.


They made their guns out of iron, not steel. There is a world of difference is drilling and tapping iron of any kind to carrying out the same operation in steel.
 

TFoley

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They made their guns out of iron, not steel. There is a world of difference is drilling and tapping iron of any kind to carrying out the same operation in steel.

I ought to have added that It was not until later on in production that the Royal Small Arms Factory at Enfield changed production of the Snider rifle and carbine to first of all 'steel barrel' and then 'all-steel'. By way of contrast, Winchester first produced a steel rifle in 1894 - the Model 1894 was the first commercially-made firearm in the USA to be made of steel.
 

TFoley

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Thanks for tutorial.

Hey, the question was asked, and I responded. I'm an ex-military teacher/instructor with ten years experience teaching a wide number of technical subjects in military intelligence - five years as an INTEL School Chief Instructor where I taught sixteen technical subjects to NATO and other students from all over the world, including the USA, where I also taught in one of your military INTEL establishments. I went on, post-retirement, to teach another bunch of wide-ranging technical subjects in Japan for almost eight years, to another kind of student, only some of whom were even vaguely military.

I open my big gob - I teach - I can't help it, it's how I'm made, and I'm not going to apologise for it.
 
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