First off I am saying that I am not a licensed gunsmith or any type of gunsmith for that matter; I consider myself a tinkerer. Also I no longer own a metal lathe and haven't for probably 4 years. The desk that I use to have the lathe mounted is now my reloading bench in the house. I am posting to see if others use this procedure and to discuss pros and cons. I am not a professional and do not profess to be. I am not qualified to pass tools to half of the craftsmen who post here.

I have built a few guns for myself through the years. I am self taught as far as operating my old 1941 vintage 9" Southbend metal lathe. My friend, who is an accomplished gunsmith taught me how to thread barrels.

Here is an overview of my former setup.



Headstock



Tailstock



Faceplate and Dog



Shank



Progress: Here is the relief groove (I am not good with a parting tool), the thread portion turned to major thread diameter, and excess barrel shank turned to bolt body diameter for extra room to work on the threads.



Threads scratched to verify pitch



Threads after .040" advance



Threads "V'd" up. I don't remember if this was final fit or just a view of V'd threads. At this stage I would remove the barrel and Dog as a unit and test fit to the individual action for a very nice custom fit.



My custom crown, essentially a protected 11 degree target crown for a hunting rifle. I don't know if it negated the benefits of the 11 degree crown or not.



Again the intent of this post is to show one way to cut barrel threads. I know the threads aren't perfect, but they are better than some prethreaded barrels that I have gotten from others; that plus they fit a whole lot better and give flexibility over shank profile. This particular barrel was a 280 Ackley Improved so there is a hefty shank on it. For a 257 Roberts or similar, I prefer only 7/8" of shank forward of the relief groove.

quote:

Originally posted by airgun1:
First off I am saying that I am not a licensed gunsmith or any type of gunsmith for that matter; I consider myself a tinkerer. Also I no longer own a metal lathe and haven't for probably 4 years. The desk that I use to have the lathe mounted is now my reloading bench in the house. I am posting to see if others use this procedure and to discuss pros and cons. I am not a professional and do not profess to be.

I had a JET 12x36 belt lathe mounted to a desk years ago but when I got rid of the lathe, the desk went with it. I use a regular bench for reloading. The pro's are, it is taller so my back doesn't get so tired. The cons, no real drawers to put stuff. If your lathe desk works good for you then I wouldn't worry about it. And, you don't have to be a professional to enjoy using a desk to reload.

Some of the finest, most accurate rifles ever made came from the old masters who had lathes far less modern than those that even rank amateurs have today. Quality is not in the machine, it's in the operator.

I believe there's only one thing I'd do different. I'd turn that "excess barrel shank" down to minor thread diameter to help as a gauge and then turn it to bolt diameter when you're ready to try the fit.

Oh wait. One more thing. Get a shop-Vac.

Ray

Ooops, I should have read to the bottom and waited for the pictures to down load (slow speed here).

That's quite the lathe. I think those older lathes like that are cool looking. As to your set up, I might suggest removing that little stub from the breech end and placing the center closer to the threads, right where the mouth of the chamber will be. That will go a long way in helping to prevent deflection. In fact, anytime you can set up right next to the area you are turning, your finish will be better and tolerances more controlled. I don't see any cutting oil.

How did you set up to cut the chamber? The crown looks fine. I use a recessed 11 degree crown myself. Looking good.

The pics were taken a few years ago to show a friend how to do it. I cleaned the cutting oil up. My friend taught me to use the bolt diameter stub for 2 reasons, room to work, and also because he didn't beleive in live centers for precision work.

That old lathe was true and I was not inferring that my errors were caused by it. The operator was definitely the weak link in the operation.

I chambered in a 4 jaw chuck. Once the threads were cut to depth, I would cut a good concentric with the bore shank in front of the threads for the chuck to hold. Used a small open end wrench to hold the reamer and advanced with the dead center in the tail stock. I know my chambers weren't match grade, but they weren't as wallowed out as some professionals' work that I had seen.

quote:

Originally posted by airgun1:
My friend taught me to use the bolt diameter stub for 2 reasons, room to work, and also because he didn't beleive in live centers for precision work.

If you ever get back into doing this again, buy a quality live center. Also, you can reduce potential alignment errors by doing all your machining with 1 set up.

I started the hobby 10 years ago and got this method from Bryant when I asked at the Yahoo gunsmith forum:

http://www.bryantcustom.com/articles/rebarrel.htm

25 rifles later, still doing it the same way.

tnekkcc,
Mike Bryant is a very sharp and honest gunsmith. He is a thinking man and is not above listening to another persons idea. I have a lot of respect for him.
Butch

Kinda hard to argue with folks like Ed Shilen and P.O. Ackley (who also advocated & taught the steady-rest method).

Also, there's a good reason why most if not all machining books recommend threading between centers. For you folks who thread while clamped in the headstock, I wish you luck. Kinda reminds me of learning to fly; when we advanced to retractable gear, the instructor lectured me about landing 'gear up'. He said that there are only 2 kinds of R/G pilots: those who HAVE, and those who WILL!

IMO same goes for slippage in the headstock while threading, I've tried it both ways and had trouble when clamping. Now, a good collet clamp might solve this, but...

I thread between centers and chamber in the steady but I'm not a Benchrest smith. OTOH Ed Shilen IS a Benchrest smith and he does it the same way.
Regards, Joe

Not anymore J.D.,
I gave him a lesson in my shop doing it in the headstock. His shop is still doing customer's barrels in the steady rest. Personally I wouldn't trust 2 setups to do a chamber job. In the headstock you can do the complete chamber job in one setup without moving the barrel. Switch the barrel around and crown it and you are done. I'm certainly not saying a good shooting rifle cannot be done between centers as many have been. I'm not aware of any competition gunsmiths doing it between centers.Mike wrote his article a few years ago and still does it in the headstock with a few mods to his setup. In the olden days BR smiths did it in the steady rest, no more.
Butch

I could not have ever dreamed of chambering in my steady rest. The 9" SouthBend steday rest is like a toy! Great responses, thanks guys!

I realize I'm not gonna change some folks' minds about this, and that's fine with me. I'm not trying to convince anyone that the steady is better, only saying that threading in the headstock has disadvantages and leaves the door wide open for Murphy to strike. Like retractable gear, it also has many advantages that far outweigh the disadvantages in many minds, but the disadvantages are still there and must be considered.

I also know that:
A)The smithing schools still teach the steady method, and they still use 9" South Bends in some cases.
B)Any competent toolmaker can name many different ways of accomplishing any task in a proper manner but each has his favorite method.
C)The individual workman & his application of his expertise is far, far more important than either his tools or his method, in fact IMO it's far more important than both put together.
D)The headstock doubles the effect of any tailstock error while the steady cuts it to ~20%.
E)I have experienced slippage when threading in the headstock.

You keep doin' it your way and I'll keep doin' it mine, no problems on this end.
Regards, Joe

would it be a too big a favor to ask for somebody to post a pic with some labels of parts (I have a simple southbend lathe book somewhere I bought to try and understand this stuff but have misplaced it) and then explain these two methods being discussed? I'm not a machinist and will never do this sort of thing but find it immensely interesting and would like to understand the process.

Thanks.

Red

To turn a barrel "on centers", you need a dead center in the headstock through hole, a face plate instead of a chuck, and a dog to drive the barrel via the face plate slots as shown in pics 2 and 4

You will also need a dead center or a high quality live center in the tailstock bore as shown in pics 1,3,5-9

My steady rest is pictured in the background between the headstock and the carriage in pic 2, and pic 4. It is dark blue. I don't know if it is original to a 9 inch Southbend or not, but I wouldn't use that particular steady rest for anything as critical as chambering. There are way stouter steady rests out there. A steady rest is like a secondary set of lathe chuck jaws a little further down the lathe bed from the headstock for lack of a better description.

I have threaded between centers and screwed it up.
I have chambered in the steady rest and screwed it up.
I have threaded and chambered in the 4-jaw chuck and screwed it up.

I have seen others build great rifles done in the steady rest.
I have seen others build great rifles done in the head stock.


It all reminds me of this story:

quote:

A famous photographer decided to have a meal at a famous restaurant. The waiter recognized the photographer and returned to the kitchen reporting the photographer's presence to their world famous chef. The chef felt it wise to visit the photographer's table and acknowledge the photographer's presence. Straight away the chef left his kitchen and approached the photographer stating, "I have long been a follower of your work and your images are simply breath-taking. You must have a really nice camera to take such wonderful pictures". The photographer replied, "Your food is excellent. You must have a really nice stove."

quote:

Originally posted by tnekkcc:

quote:

A famous photographer decided to have a meal at a famous restaurant. The waiter recognized the photographer and returned to the kitchen reporting the photographer's presence to their world famous chef. The chef felt it wise to visit the photographer's table and acknowledge the photographer's presence. Straight away the chef left his kitchen and approached the photographer stating, "I have long been a follower of your work and your images are simply breath-taking. You must have a really nice camera to take such wonderful pictures". The photographer replied, "Your food is excellent. You must have a really nice stove."

AMEN, Brother!
Regards, Joe

quote:

A famous photographer decided to have a meal at a famous restaurant. The waiter recognized the photographer and returned to the kitchen reporting the photographer's presence to their world famous chef. The chef felt it wise to visit the photographer's table and acknowledge the photographer's presence. Straight away the chef left his kitchen and approached the photographer stating, "I have long been a follower of your work and your images are simply breath-taking. You must have a really nice camera to take such wonderful pictures". The photographer replied, "Your food is excellent. You must have a really nice stove."

[/QUOTE]

That may be the best summation I have seen.

That is a fine example of classic methodology on a classic old machine.
When I first started gunsmithing my mentor did his chambering in the headstock but did his threading between centers.
He was having a bit of trouble with oversized chambers and I discovered his tailstock sat low so I started chambering in the steady.
I went back to chambering in the headstock later on (new lathe) and mostly still do so. Still, using the steady after threading between centers is a viable method and, with an old lathe with small headstock bore, it's the only way to do it. Regards, Bill.

quote:

In the headstock you can do the complete chamber job in one setup without moving the barrel. Switch the barrel around and crown it and you are done.

And that is how Dwight Scott taught us how to do it. And it works great.

Need to regrind that thread cutting tool to 60 degrees. Those threads look to be damn near 90 degrees. They are ruined.

quote:

Originally posted by D Humbarger:
Need to regrind that thread cutting tool to 60 degrees. Those threads look to be damn near 90 degrees. They are ruined.

55 degs, looks like a mauser barrel.
Don

I was hoping the picture was deceptive as far as thread angle went!
From a practical standpoint, as long as the thread face is 27.5 degrees, it will work out OK under load(kind of a modified buttress) but it isn't, of course, ideal.
The chatter with the parting tool when cutting a relief with the barrel between centers is a common problem due to flexibility in the set up; especially with a light machine. For relief cuts, I ground a narrow tool with a radiused (sp?) nose to produce a radius at the corner of the relief. It cuts smoother and a corner with a radius is stronger.
As I mentioned before, the technique is still viable and is still used by many who use lathes which are too small or too big or for the sake of expediency. I don't think it is the best way to fit a BR barrel but I fitted and chambered the barrel on the best LV rifle I ever shot just this way 30 years ago. Like I said, vintage methodology on a vintage machine. Regards, Bill.