Chambering question

B

Bnhpr

Ben Hooper
Hello, I'm a part time machinist (I'm an engineer actually) that is starting to get into rebarreling rifles.

I have a South Bend lathe, and was wondering why I could not thread and chamber the barrel in a 4 jaw chuck, instead of using a steady rest?

Is there some sort of tool that I could put down the bore to dial the barrel in with?

Is a 4 jaw just not precise enough for a chamber?

Any feedback is appreciated.
 
You need to make a spider for the spindle. Midway has a book "The Gunsmith Machinist" that shows how to make a spider and various methods of chambering a bbl. Also has a good bit of info on truing a Remington action.

Grizzly just put out a chambering video that I highly recommend.

Good luck
 
I think you will find that most thread and chamber in a 4 jaw or 6 jaw chuck rather than using the steady rest. There are several methods of indicating in a barrel. look through the archives for appropriate threads. It's best to support the muzzle end of the barrel in a centering device on the oposite end of the headstock.
 
Wow, good stuff. I guess if you make a tool and bore the chamber, you only need a finish reamer?

I used to do a lot of small tool boring, making model steam engines.

I guess you calculate angle by measuring a Go gauge? Or put the reamer between centers and indicating off that?

Also, boring should maintain concentricity, assuming your dialed in right.

I will get that DVD to get up to speed, so I'm not asking you guys too many stupid questions.
 
How big is the spindle hole in your South Bend?? Out of curosity what angle would you need to calculate??

Mike Swartz
 
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Chambering

Pacific tool & Gauge Makes indicator rods for every caliber. They are tapered and fit in the bore until they are snug. It is very easy to dial in a chamber with one of these rods. They are $37.00 for each caliber. Ross
 
rem40xb1 said:
Pacific tool & Gauge Makes indicator rods for every caliber. They are tapered and fit in the bore until they are snug. It is very easy to dial in a chamber with one of these rods. They are $37.00 for each caliber. Ross
Click to expand...

The Grizzly DVD shows a very interesting way to dial in the bbl.
 
Chambering

If you will look on the Forums, I think there are several threads running right now on this very subject. Read them, and then if you have questions, we will be glad to answer them to the best of our ability.
There are many chambering methods that are tried, some are quite sound, and some have "stacked tolerance" stamped all over them. Keep in mind. The one thing that really counts is the finished product.......jackie
 
Mike Swartz said:
How big is the spindle hole in your South Bend?? Out of curosity what angle would you need to calculate??

Mike Swartz
Click to expand...

I'd estimate 1.5", but I'm not home to verify it.

The calculated angle would be case taper for the specific cartridge

The other idea that I had was to put my finish reamer or go gauge between centers, and indicate along a flute, so I can set the angle of the compound rest, paralell with the cartridge. This will allow you to rough out the chamber with a tool, instead of a roughing reamer. Good stuff.

Ben
 
jackie schmidt said:
If you will look on the Forums, I think there are several threads running right now on this very subject. Read them, and then if you have questions, we will be glad to answer them to the best of our ability.
There are many chambering methods that are tried, some are quite sound, and some have "stacked tolerance" stamped all over them. Keep in mind. The one thing that really counts is the finished product.......jackie
Click to expand...

Thanks for the information Jackie, I'll be happy to read them. I've been reading books and watching videos, but you can't ask a book a question.

These threads contain some great info.

I've been trying for years to get some tips from a legendary barrel maker/machinist that lives by me, but he's not interested. He's old, mean and deaf, but he builds barrels that shoot like I've never seen before. He's got a memory like no one I've ever met before. He remembers serial numbers from rifles he sold years ago. So, I've decided to just go out on my own and learn it myself.
 
I originally

put my PPC reamer between centers and indicated along a flute to get the proper taper bore angle. Then, because I fit a lot of PPC and BR barrels I made a witness mark on my compound so as to be able to set the angle without indicating it in every time.

Merry Christmas
Shelley
 
Bnhpr, If you are interested I have spindle Spyders for the South Bend lathe on ebay all the time. They usually sell for $20 to $30 USD. They fasten to your spindle with flat head set screws and the barrel is trued with 4- 3/8 nylon set screws. I have sold more than 100 of these and they are well received. Kenny [ sicero1@aol.com ]
 
Bnhpr, making a spider is a nice easy shop project ....... I made mine from some scrap thickwall DOM tubing, bored one end to a snug sliding fit ( no shake ) and use a couple of screws to retain it.

To prevent marring the end of my spindle when I first fitted the spider to the spindle I dropped a couple pieces of lead shot into each hole before tightening down the retaining screws ( oil the spindle so they don't stick ). They deformed to match the surface of the spindle and provide a very tight clamp up with no scratches.

Having said all that, the ones sicero is selling on e-bay sure look pretty :) I like the idea of the nylon screws ..... I'm always fiddling with little copper shims to prevent marring the barrel.
 

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OK, let the criticism begin..

Let the criticism begin....

Plan on making some soft ends for the bolts.
 

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Bnhpr said:
Let the criticism begin....

Plan on making some soft ends for the bolts.
Click to expand...

That will work. Whats the i.d.? I made mine 2.0" i.d. in order to accomadate all size actions including flat bottoms with integral dovetails...............Don
 
Bnhpr said:
Let the criticism begin....

Plan on making some soft ends for the bolts.
Click to expand...


how long is the distance from the front of how you hold the bbl to the muzzle end on the spyder ??

think the spyder is long...but if it works so be it.( cut it in half and rotate the bolts 45 degrees from the others)

just my 2 cents worth...i have yet to chamber a bbl....maybe only 1 cent.

mike
 
5O'ClockCharlie said:
I think he's made an action trueing fixture mike.

The fixture gets held in the 4 jaw, action mounted inside the fixture with a close fitting mandrel sticking out the front. the mandrel is indicateds to run true using 2 indicators while the forward and aft "cat's head" are adjusted.

see: http://www.bryantcustom.com/articles/true.htm
Click to expand...

That's my plan, to use it for action trueing for the rem 700 long or short actions.

I am thinking about making an expanding mandrel that will tend to self center. With the mandrel they use, there will have to be clearance?

I've never heard of it in gunsmithing, but I've used these when centering turbochargers.
Also, one could fit several sized actions.
 
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