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Chambering barrel

creekrat

Plastic
Joined
Dec 24, 2018
So Im looking to build a lr/elr hunting rig in 300wm. Looking to use a Bighorn SR3 and a carbon wrapped barrel. My friend that has a lathe and does some smithing and has threaded and crowned barrels for brakes. What he does not have is a spider. My question is is it feasible to chamber a carbon barrel on centers without marring the carbon in the steady rest and if so how did you manage this?
 
Viper Chambering FIxture

So Im looking to build a lr/elr hunting rig in 300wm. Looking to use a Bighorn SR3 and a carbon wrapped barrel. My friend that has a lathe and does some smithing and has threaded and crowned barrels for brakes. What he does not have is a spider. My question is is it feasible to chamber a carbon barrel on centers without marring the carbon in the steady rest and if so how did you manage this?

I would highly recommend contacting Bob at the site listed below. Take a look at his cambering fixture - second item on the page as you scroll down. His contact information is at the bottom of the page. The man is a master machinist and a prolific champion 1000 yard and F Class bench rest shooter....knows his stuff.

F Class Feet for The Viper

Tell him Dale in Reno, NV says hello.
 
Between centers with a steady on a cf barrel I don’t think would work very well.
Ideally you’d want to use something like the Tru Bore alignment system or at least a cat head Chuck with a sleeve fit over the barrel where the set screws touch it.
 
^^^
You can use a spider in the steady as mentioned here, or you can press-fit a sleeve over the barrel just ahead of the area to be worked.

Same technique as used when needing to do a re-crown, or threading a muzzle between centers. If necessary depending on barrel taper, you may need to bore to match the contour (I've also done a quick cast with epoxy in a sleeve so it precisely fits the contour). Place it on the barrel with the breech in a precision live center (or dead center with some STP lube as it's a quick op, make a facing cut to true the OD to the bore. Place the steady to ride on the trued collar and get to work.

I still chamber between centers sometimes, with a steel barrel the truing cut is done directly on the breech cylinder of the barrel, same idea here except use a sacrificial sleeve over the cylinder instead.

If the spindle bore is large enough, it's pretty simple to make a spider to fit if you'd rather chamber it through the headstock.
 
^^^
You can use a spider in the steady as mentioned here, or you can press-fit a sleeve over the barrel just ahead of the area to be worked.

Same technique as used when needing to do a re-crown, or threading a muzzle between centers. If necessary depending on barrel taper, you may need to bore to match the contour (I've also done a quick cast with epoxy in a sleeve so it precisely fits the contour). Place it on the barrel with the breech in a precision live center (or dead center with some STP lube as it's a quick op, make a facing cut to true the OD to the bore. Place the steady to ride on the trued collar and get to work.

I still chamber between centers sometimes, with a steel barrel the truing cut is done directly on the breech cylinder of the barrel, same idea here except use a sacrificial sleeve over the cylinder instead.

If the spindle bore is large enough, it's pretty simple to make a spider to fit if you'd rather chamber it through the headstock.


How does a face cut " true the OD to the bore"?
 
After spending that much on a barrel blank, I wouldn't want it chambered between centers. Building a spider isn't hard.

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Run the steady on the barrel tenon. It’s still steel, yes?
But it's not likely centered on the bore. You would typically take a light cut on the cylinder portion of the contour, this is not practical on a proof.

Build a spider, buy a prefit barrel or bring it to a gunsmith.

Sent from my Pixel 2 using Tapatalk
 
But it's not likely centered on the bore. You would typically take a light cut on the cylinder portion of the contour, this is not practical on a proof.

Build a spider, buy a prefit barrel or bring it to a gunsmith.

Sent from my Pixel 2 using Tapatalk

Hmmm...OK. Don’t you still have to cut the tenon diameter and thread a Proof? Guess I’d better try one. It’s carbon wrapped in the middle with steel showing on both ends, yes? I fail to see why chambering between centers won’t work just like any other barrel. I’m no pro but if I didn’t have a spider I would put good centers in each end with a piloted center cutter, true the muzzle end if that makes you feel better, flip it around, drive the muzzle and bring the breech up to a center in the tailstock, cut the tenon, thread it, run the steady fingers on the threads and chamber it. I then would screw a trued threaded collar on the threaded tenon, flip it over again and do my work on the crown. Betcha it would shoot just as well as one setup in a spider.

Still plenty of fake wood winning barrels being chambered between centers. Setting up in a spider is fine but sometimes it doesn’t work due to a worn out machine or barrel limitations. A good Smith will turn out a quality product anyway.

I really really really doubt that a lot of the big name smiths go to all the setup trouble their websites say they do...chamber jobs would be $1000 labor if they did. I had a very competitive switch barrel BR rifle on a Stolle Panda with multiple Harts built. I was present for the work as an observer and there was not a spider, carbide boring bar, or a test indicator or a Gritter rod in sight. [emoji1]

This is just how I’d do it. I don’t have to make a customer happy. I’m the customer. Ha! Just suggesting to the OP that there could be another way to go if he wishes to tackle it. As always, free advice worth the price.
 
Chuckle chuckle, Still plenty of fake wood winning barrels being chambered between centers. Setting up in a spider is fine but sometimes it doesn’t work due to a worn out machine or barrel limitations. What in the 'ell is different in chambering with a "worn out" machine with any chambering method? With a tight headstock and bearings, the ways are not an issue. Tailstock alignment is not an issue either.
If you have chambered a barrel before and understand good machining practice, you will understand what I'm saying.
If this PDF opens for you I believe it has 130+ pages about chambering. 130 page PDF of different chambering methods | Shooters' Forum
 
Chuckle chuckle, Still plenty of fake wood winning barrels being chambered between centers. Setting up in a spider is fine but sometimes it doesn’t work due to a worn out machine or barrel limitations. What in the 'ell is different in chambering with a "worn out" machine with any chambering method? With a tight headstock and bearings, the ways are not an issue. Tailstock alignment is not an issue either.
If you have chambered a barrel before and understand good machining practice, you will understand what I'm saying.
If this PDF opens for you I believe it has 130+ pages about chambering. 130 page PDF of different chambering methods | Shooters' Forum


Thanks for the link and I certainly do appreciate the condescending chuckle[emoji6]. I saved that and printed it several years and barrels ago. Lots of good stuff. Please keep the helpful tips coming, plenty to learn yet.

If you have success running through the headstock then please do so. As the PDF suggests, there are many ways to skin a cat. I’ve got a long, 1.30 diameter headstock...oddly enough a high tail stock and the quill runs about .002 out at full extension. I did build a spider for it.
fb41e7939203d356d131663a572d7a03.jpg
Old import Enterprise out of a prison workshop[emoji41]. Used an spare concrete slump cone for the sheet metal work. There’s a thou to thou and a half play in the headstock bearings as best I can measure depending on if it’s warmed up or not. That’s about as worn out as I want to get working near the headstock, I prefer to spread the error out down to the other end but that’s just me. I’ve done 25” and longer barrels “chucked” in the headstock with this store bought spider I believe is intended for the other end.
e007d8b53c5cc8b4e008db8def0f81b1.jpg
. Turned out to be a damned nice .35 Whelen even though I did have to mail it off to the lower United States for Cerakote :
f7c874dc4012c992291eb95d9b3d15e8.jpg
4d10d6b5d0dc3b4cc3803651b51ab898.jpg
. No doubt they’d all be in the same hole with better machining practices but that’s the best I can do at my current level.

I’ve built pushers and even tried a Bald Eagle. Didn’t like either much but the barrels still somehow shoot well. For my situation, between centers works best. I think that way is included in the 130+ pages?

Here’s the last one I did, wrong handed again but it does shoot even though I cheated with a Borden action (makes even me look good). No glorious group pics for the bragging board, unfortunately it was still raining the day I put it on paper and ruined my target in the back of the truck before I got home. Dog ate my homework [emoji1].
aee688411809d6b5d14bb987db391fb4.jpg


Wonder how the OP is coming along anyway...
 
Thanks for the link and I certainly do appreciate the condescending chuckle[emoji6]. I saved that and printed it several years and barrels ago. Lots of good stuff. Please keep the helpful tips coming, plenty to learn yet.

If you have success running through the headstock then please do so. As the PDF suggests, there are many ways to skin a cat. I’ve got a long, 1.30 diameter headstock...oddly enough a high tail stock and the quill runs about .002 out at full extension. I did build a spider for it.
fb41e7939203d356d131663a572d7a03.jpg
Old import Enterprise out of a prison workshop[emoji41]. Used an spare concrete slump cone for the sheet metal work. There’s a thou to thou and a half play in the headstock bearings as best I can measure depending on if it’s warmed up or not. That’s about as worn out as I want to get working near the headstock, I prefer to spread the error out down to the other end but that’s just me. I’ve done 25” and longer barrels “chucked” in the headstock with this store bought spider I believe is intended for the other end.
e007d8b53c5cc8b4e008db8def0f81b1.jpg
. Turned out to be a damned nice .35 Whelen even though I did have to mail it off to the lower United States for Cerakote :
f7c874dc4012c992291eb95d9b3d15e8.jpg
4d10d6b5d0dc3b4cc3803651b51ab898.jpg
. No doubt they’d all be in the same hole with better machining practices but that’s the best I can do at my current level.

I’ve built pushers and even tried a Bald Eagle. Didn’t like either much but the barrels still somehow shoot well. For my situation, between centers works best. I think that way is included in the 130+ pages?

Here’s the last one I did, wrong handed again but it does shoot even though I cheated with a Borden action (makes even me look good). No glorious group pics for the bragging board, unfortunately it was still raining the day I put it on paper and ruined my target in the back of the truck before I got home. Dog ate my homework [emoji1].
aee688411809d6b5d14bb987db391fb4.jpg


Wonder how the OP is coming along anyway...








Well, we did get off topic.
 








 
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