Barrel Chambering on Centers

T

trouble

Guest
My headstock on a LeBlond lathe is too long for anything under 28" so need to chamber on centers. What is the most accurate method for benchrest barrels? Best tooling etc.
 
Seems one would need to chuck one end of the barrel and run the other end in a steady rest.

Mike Swartz
 
A few months ago someone posted an interesting idea on this forum.
Put a spider on both ends of a pipe, clamp one end in the chuck and spin the other in a steady rest.
 
I use a dead center fit into the back end of my spindle for doing short barrels. I've chambered XP barrels as short as 15" in my Kent using this method with good results. The dead center is a slip fit up into the spindle and is held in place with one of the 4 set screws that I use for centering the muzzle end of long barrels. Once I get under about 24", I have to go to the dead center in the spindle. I don't chamber in the steady rest although I have done a few in the past so can't be of much help to you in that regard. The few I did, I cut a 60 degree dead center in the chuck. Then ran the barrel between centers using a lathe dog on the muzzle end running at the chuck, threaded the barrel between centers taking it out of the lathe to check for thread fit. Once the threads were alright, then turned a flat on the muzzle end. Chucked the muzzle end flat indicated in on the outside of the flat that was turned concentric between centers and chambered the barrel with the top of the threads running in the steady rest. I prefer a small flat on top of the threads whether the threads are cut between centers or in the headstock. The small flat works well for running in the steady rest on the threads.

As with all chambering, there is more than one way to skin a cat. Results are only as good as the barrel will shoot on paper. I wouldn't worry too much about using a dead center in the back of the spindle though. The current method that's going around to push the muzzle around to get two point alignment on the chamber end shows that how close to dead true the muzzle is running doesn't make much difference as long as the chamber is in line with the bore of the barrel. I really think a lot of what we do and the extremes that we go to get there are largely in our mind and may not make as much difference as we think it does. I'm sure others will disagree as everyone has an opinion and mine is just that, my opinion. If when you get done with the barrel and it shoots well, then you've done a good job. The trick is to develop a method that will work in your particular lathe and get results that will work.
 
Right On !

Mike Bryant said:
I use a dead center fit into the back end of my spindle for doing short barrels. I've chambered XP barrels as short as 15" in my Kent using this method with good results. The dead center is a slip fit up into the spindle and is held in place with one of the 4 set screws that I use for centering the muzzle end of long barrels. Once I get under about 24", I have to go to the dead center in the spindle. I don't chamber in the steady rest although I have done a few in the past so can't be of much help to you in that regard. The few I did, I cut a 60 degree dead center in the chuck. Then ran the barrel between centers using a lathe dog on the muzzle end running at the chuck, threaded the barrel between centers taking it out of the lathe to check for thread fit. Once the threads were alright, then turned a flat on the muzzle end. Chucked the muzzle end flat indicated in on the outside of the flat that was turned concentric between centers and chambered the barrel with the top of the threads running in the steady rest. I prefer a small flat on top of the threads whether the threads are cut between centers or in the headstock. The small flat works well for running in the steady rest on the threads.

As with all chambering, there is more than one way to skin a cat. Results are only as good as the barrel will shoot on paper. I wouldn't worry too much about using a dead center in the back of the spindle though. The current method that's going around to push the muzzle around to get two point alignment on the chamber end shows that how close to dead true the muzzle is running doesn't make much difference as long as the chamber is in line with the bore of the barrel. I really think a lot of what we do and the extremes that we go to get there are largely in our mind and may not make as much difference as we think it does. I'm sure others will disagree as everyone has an opinion and mine is just that, my opinion. If when you get done with the barrel and it shoots well, then you've done a good job. The trick is to develop a method that will work in your particular lathe and get results that will work.
Click to expand...



Very well said Mike, I like your philosophy. :)

Gene Beggs
 
Thanks JJ nd Mr Bryant. I knew there had to be several ways to chamber not just using the headstock. Too bad Mr Swatz only can make smart comments.
 
trouble said:
Thanks JJ nd Mr Bryant. I knew there had to be several ways to chamber not just using the headstock. Too bad Mr Swatz only can make smart comments.
Click to expand...
You are trouble aren't you. Mr Swartz happens to be one of the top tool and die makers in the US.
 
Trouble

I do barrels on a Pratt & Whitney Tool Room Lathe that has a long headstock. I have a way that I figured out to still do barrels in the headstock.

Go to the search feature and just type in "jackie chambering a barrel" . Scroll down about 1/2 way, and you will see a thread by Gary Walters featuring me doing this, complete with pictures...........jackie
 
Trouble,

I chambered a 30 BR bbl 5 groove Broughton in a similar fashion as Mike described. I was very pleased with it.

I turned a piece of T6061 to slip into the spindle. On the end I left a tit, around .300 tapered to .310, over 1/2" and tapped it into the uncrowned muzzle with a plastic mallet. The other end in a 4 jaw. I re-indicated the throat after threading, coning and drilling/boring, and it was still fine.

Ben
 
Here's my set-up

563925605_mRNpx-M.jpg


563924332_UkDRu-M.jpg
My 16" South Bend.

Mark
 
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