Gunsmithing chambering with a collet chuck?

[ken226]

Anyone do it?

My collet chuck has less that .0002 runout, so would this be a viable method? Holding the muzzle in a 5c collet and chambering on a steady rest.

I could turn the blank on centers the get the stump end at the right diameter to fit a 5c collet and with the chamber end on a center, take a light cut to true it up, if its not already. Then mount up the steady rest, remove the center and ream the chamber.

Anyone ever try this method?

Another way might be to run the barrel through the spindle bore, chuck the chamber in a collet and support the muzzle end in a spider. Indicate and true up the muzzle end with the spider and ream the chamber in a collet? I think to do this would require the chamber diameter be turned down to 1.125 though since that's the largest diameter a 5c collet can take.

I was just trying to think of some ways to let my new 5c collet chuck pay for itself

 

[Al_Ski]

Another way might be to run the barrel through the spindle bore, chuck the chamber in a collet and support the muzzle end in a spider. Indicate and true up the muzzle end with the spider and ream the chamber in a collet? I think to do this would require the chamber diameter be turned down to 1.125 though since that's the largest diameter a 5c collet can take.

The chamber end of the barrel has to pivot inside a four jaw chuck. You'd be bending the barrel by trying to indicate the muzzle end in while the chamber end was in a collet.

 

[ugsly]

I believe Chad uses a collet chuck when chambering, maybe he will chime in and explain his method.

Casey

 

[Killswitch Engage]

why wouldnt you just use a 4jaw chuck with a gimble ring and a outboard spider? having a large purchase on the barrel on either end causes stress in the barrel and forces it in a direction it doesnt want to go. i would think your new lathe has a big enough spindle bore to accomadate most barrels?

 

[bptactical]

While your collet may have near zero runout the barrel may very well not. What the OD is doing is irrelevant. Use the 4 jaw gimble ring setup described above.

 

[Bill Larson]

Using a collet would require perfect concentricity with O.D. to bore.Also the collet would try to align the profile thru the tailstock,making the adjustable spider on the outboard ( muzzle ) actually bend the barrel in order to align the bore.That`s why alot of us us a gimble style set-up in the 4-jaw or use a steady rest...either will not induce barrel bend.

 

[colchester]

You can do it as you have described above Here is a thread on the subject with the appropriate details
http://www.snipershide.com/shooting...ing/197558-chambering-barrel-steady-rest.html
He does it basically as you are describing and the results speak for themselves. I would add I prefer to do it through the headstock when I can but very good results can be achieved by using a steady rest if you pay attention to details. Enjoy

 

[cal50]

If you can get the bore indicated in and the collet has adequate gripping / chucking strength its "yes".

 

[chipsfan]

One of the canadians on prectical machinist uses a collect chuck on the headstock when chambering between centers. It seems to work well for him.

 

[300sniper]

One of the canadians on prectical machinist uses a collect chuck on the headstock when chambering between centers. It seems to work well for him.

Yep, speerchucker over there. I want to say he puts the barrel between centers and turns a shank at the muzzle end concentric to the bore. He then puts that shank in his collet chuck and the breech end into a center. The tenon is created and threaded. A steady rest is placed over the threads and the counterbore is made. I think at that point he slacks the steady rest a bit to allow the tenon to float. Then with a collet chuck in his tailstock holding the reamer rigid, he reams the chamber, essentially using the reamer as the center. It makes sense and seems to work well for him. There are a few things I personally don't like about that method but it has been hashed out enough on the other forum that I'm not going to get into it here.

 

[MikeeBooshay]

I've been thinking about a collet chuck, maybe mounted in something like 308Nates system. Collet is going to be the best work-holding, very stiff, won't mar the finished OD of the barrel. I like to indicate the barrel near where the throat of the chamber will end up, if that is true, I don't really care where the muzzle is.

A method like that, you wouldn't be limited barrel length chambering thru headstock, the muzzle would be left in the spindle where it ended up after setting the breech up. Rather than completely trust the rods Nate uses, I'd still likely check the barrel in a couple places with a long reach DI though.

I'd like to see someone's setup if they are already doing it though, seems like a solid method.

 

[cal50]

5C collets max out at smaller diameters. If you can use a 5C collet then you are good to go. I would take a clean up cut of the barrel OD first then use a collet. If the 5C collets are too small and have larger collets move up in size.