Heavy Copper-Wire Ring and Octagon Barrel

H

HiWall

New member
I will soon be threading and chambering an octagon barrel and am wondering what is best to use between the barrel's octagon sides and the jaws of a 4-jaw chuck (so the barrel can pivot easily when adjusting the spider)? I have used the heavy copper-wire ring on a round barrel but I think a round ring on an octagon barrel will not be the best shape to use due the amount of distortion the chuck's jaws will have to make to compress the ring down to make contact to the octagon flats. I can try something like two pieces of copper wire each bent into "L" shapes but if someone has a solution that is proven I'd like to consider it before I get into this next project.
 
Hammer

Make a copper wire ring, but shape it to the barrel first with a hammer before chucking. It could even be a square as it only needs to touch 4 opposing flats.
 
Either the 2 "L"'s or a square with the opening at the corner will be just fine. The square will be easier to handle and stay put when you're chucking
& un-chucking.
 
Rflshootr said:
Either the 2 "L"'s or a square with the opening at the corner will be just fine. The square will be easier to handle and stay put when you're chucking
& un-chucking.
Click to expand...

The square shape sounds like it might work. My concerns is that heavy forming of the wire to the profile of the octagon shape might flatten the wire too much and then limit the barrel from pivoting easily. I'll see what will be practical to do when I start working with the #4 wire.

Thanks for the comments!
 
Just curious, has anyone tried using something spindle-bore sized, with a pilot (or center) that fits the bore of the barrel? Do spindle IDs run true? Do any of you guys thread (etc) barrels between centers, and chamber using a steady-rest?
F1
 
Hal said:
Some guys just put the copper wire around each jaw of the chuck.

Hal
Click to expand...

I made up four straight-sectioned U-shaped pieces of #4 copper wire that are a tight slip fit on each and the chuck jaws. These I think will offer less resistance to jaw adjustments than say, a one-piece ring or square. I should know in about a week how well it works on threading/chambering an octagon barrel.
 
No it wasnt a cut at all! I was saying lots do chamber between centers but they dont even say it because the guys that chamber 2 barrels every 10yrs argue about their method til the actual winning rifle builder just goes away to chamber more barrels instead of argue
 
Fussy1 said:
Just curious, has anyone tried using something spindle-bore sized, with a pilot (or center) that fits the bore of the barrel? Do spindle IDs run true? Do any of you guys thread (etc) barrels between centers, and chamber using a steady-rest?
F1
Click to expand...

Thank you. Thank you. Thank you.

For years I've been thinking that was what was going on. All the while I was running an Okuma CNC lathe trying to figure out how I could do a barrel on it. It doesn't have the bed to do a barrel between centers but I'm pretty sure I could center the breach end and turn, thread, and bore the chamber all one shot. The problem to solve would be getting the muzzle end centered inside of the spindle. The one I was running had a 2 1/2 inch bore where I had room to run 2 1/2 inch stock. That kind of leaves a lot of room to insert something to get the job done. I'm not sure it would be to my satisfaction though.

While I was dreaming the machine was sold and then died. Last time I saw it is was going for $15,000.

http://sfbay.craigslist.org/eby/tls/4824340233.html
 
HiWall said:
I made up four straight-sectioned U-shaped pieces of #4 copper wire that are a tight slip fit on each and the chuck jaws. These I think will offer less resistance to jaw adjustments than say, a one-piece ring or square. I should know in about a week how well it works on threading/chambering an octagon barrel.
Click to expand...

I just finished threading and chambering my octagon (half round) barrel with these four u-shaped wire pieces and things worked out real well. No shifting of center after centering to my SB heavy 10" lathe's spindle using an Interapid .0001" DTI with a 2.75" long point. I centered a 1" long section of the bore in the area where my bullet would sit in the chamber. The bore at the muzzle then had about .012" run-out showing how the bore may not be straight end to end.
 
HiWall said:
I just finished threading and chambering my octagon (half round) barrel with these four u-shaped wire pieces and things worked out real well. No shifting of center after centering to my SB heavy 10" lathe's spindle using an Interapid .0001" DTI with a 2.75" long point. I centered a 1" long section of the bore in the area where my bullet would sit in the chamber. The bore at the muzzle then had about .012" run-out showing how the bore may not be straight end to end.
Click to expand...

I just finished doing the crown work. I did a flat crown and beveled the bore with a 1/2" dia. Brass ball (40 cal) had lapping compound. I had to resort back to a copper wire ring as this end of the barrel is round. I got too much squirreliness using the u-shaped pieces. I aligned a .700" long section at the muzzle using a .0001" DTI. The breech end had a .0025" run outdoor after aligning.
 
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