Brownells sells a square threading bit for a reasonable price too. It makes life easy.
                     Steve

quote author=harry_eales link=1220758858/0#11 date=1221167316]Uncle Ethan,

[/quote]
Sir - Those photo's are amazing!  You are indeed building a rifle the same as John Browning did.  I will study those blueprints, but I don't have your skill at machining.  My friend back in California could do as well as you, but I was learning from him when I had the opportunity to flee the liberal curtain and move to New Mexico.  I have a South Bend 9" v-belt model [early 50ties] but only about 26" between centers.  The mill is a Elgin from somewhere between 1933 and 1956 [I believe].  As you say, it is quite small but can whittle down a piece of steel a little at a time.  I have a surface grinder I am assembling, and a old Delta  bandsaw I am reworking.  I was taught that the best way to remove excess stock was by bandsaw to achieve the outside perifery prior to machining, and I had planned to build a die filer from a old gas engine I have.  I would drill the corner holes for the falling block opening, bandsaw to connect the holes and remove the center stock, and use the die filer smooth the inner surfaces prior to final material removal.  I am, however, still reading the Machinery handbook to figure out single point threading.  I haven't lived here long enough to be trusted by any of the older local machinists, so I will teach myself.  Thanks for the post and the pictures, is your shop warm enough in winter to do any work? [/quote]

Uncle Ethan,

Prior to starting work on my Borchardt copy a couple of years ago, I hadn't done amy metal machining for nearly 30 years, but machining metal is like riding a pedal cycle, once you have learned how, it's difficult to forget.

The Lathe and the Mill will be your main tools, I've never found a use for a die-filer. A Bandsaw is very useful, I agree, but I must admit I cannot see how you could use it to rough out a breech block mortice, as every band saw I have ever seen, cannot be fed through a hole in the middle of a piece of metal. The toothed band of a bandsaw is endless so I cannot fathom how it could be used in this instance.

For cutting a Breechblock mortice, a vertical milling machine is better for roughing out with perhaps a vertical slotting machine to square out the corners or an EDM wire machine to make the mortice perfect to less than 0.001" accuracy. A good surface Grinder is a nice tool to have but it isn't essential.

All you have to remember about machining metal is:- There are hundreds of 'taking off' tools and damn few 'put it back on' tools. So be careful. lol.

Some good maxims to remember when cutting metal is to measure twice, check it again and then cut once. A few small cuts are better than one large one. If you come up against a problem, ask someone, they may know more than you.

My workshop is actually my second bedroom. Being single these days I don't have a woman nagging me about working outside in a shed or garage. lol.

Learning to thread steel on a lathe isn't that difficult, but it is easier if you can find someone to show you how.

Never worry about using old machines, many of them are far better than those made today, as they were made to last. Some of the milling machines I used when in the industry were many decades old and some were made prior to 1900. They all worked well. 
Whatever action you choose to make, good luck.

Harry

Hello Trev,

I see how your method would work, but breaking the bandsaw blade, threading it through the hole and welding it back up again to rough out the hole, and then to have to break the bandsaw blade again to remove it from the workpiece seems to be as heck of a lot of trouble. 

Not many breech block mortices exceed 1" square (the size of the Borchardt mortice) and I would have thought it would have been far faster to remove the majority of the waste material with a large dia end mill and then use a smaller milling tool to remove most of the rest of the waste and finally squaring out the corners with a file or a home made chisel type tool I used on on the rear corners of my breechblock. 

I know what you mean about old engineering books, I have several, from the victorian era onwards. They're a lot more use than some of todays publications.

I'll keep posting pictures as work progresses. I thought that when I retired I'd have plenty of free time. But I'm that busy I now wonder how I ever found time to go to work.   

Harry

The proper tool in a production environment would be a broach, in a jig. 

A vertical shaper, or Keyway shaper would be useful in a semi production setting, but these are very uncommon in sizes a home shop guy is like to own.

A shaper, with the correct tooling would be a very good way of going about such a hole, though shapers are not all that common, and those with the skills needed are less so.
I have a small bench top shaper, and am just beginning to get familiar enough with it's use, to get reasonable results from it.

I would think that a hand shaper would be quite appropriate for a job such as this, as well, and would allow that time for considered thought to interfere with ones desire to speed things along. 

Hogging out most of the material on a mill or even a drill press would make much sense, from a time perspective, and for all the methods mentioned so far, it would be a requirement, as they all require some form of hole to start. 

Same for the band saw.

My explanation for the band saw was not so much to say that it was the best choice, just that it was possible, and in some cases a routine method, of clearing out the insides of closed geometry on parts that would require further work (or possibly not). The shop I work in, has two very large band saws with welders on them, one has a hydraulic feed on the table and the accouterments required to hold the work in place, to do heavy stock removal and profile roughing without having to resort to milling off large quantities of chips at a slow rate of speed.

A Die Filer would also be a decent tool, but slow. Easy enough to use, if on can keep from getting bored, and can keep from trying to speed things along by pushing the work too hard into the tool, which would cause a great deal of flex, and a resultant crooked mortise.

Even hand filing, which almost seems a lost art these days, can achieve really amazing results, if carried out with patience. If one is patient with hand filing, one eventually becomes quite skilled at removing metal where and how one wishes. I have seen some amazing work done with files.

The best way, is the one that you can get the results you require with, and have access to. 

Cheers
  Trev

They still teach you how to use a file in the gunsmithing program at TSJC here in colorado. We made a functional remington model 6 action using nothing but files....slow work and a crappy project....but I can file now.
                 Steve

Quote:


Hello Butch,

That is precisely what I did when cutting the square corners of the back of the breechblock slot on my home made Borchardt action. I milled everything out with a 1/4" milling tool and then squared the rounded corners with a chisel type tool, locked in the tool holder of my vertical mill.

Harry

Quote:


You might look here (You need to Login or Register to view media files and links). If they have the casting they should have the drawings also. The Phoenix was made by Whitney after getting in trouble with Remington on the rolling block. The trigger guard/ lower tang looks just like a Remington rolling block. I think they must have used some of the rolling block parts when designing the Phoenix.