Gunsmithing Short Barrels in a Long Lathe Spindle?

[overspin67]

Hy guys,
in our workshop we use two lathes: a short spindle one that take care of threading+chamber short barrels (< 24") and a long one dedicated to longer barrels... (see attached image)
to increase rigidity and precision, we prefer to fit the barrels through spindle hole, indicating both ends ( 6-jaws chuck from chamber end, spider 4-grains from the back end)
if we'd decide to use the big (long spindle hole) lathe, that would be preferable as it's really strong and solid, is there a reliable and accurate mean/jig to fit short barrels through the spindle and center both ends (of course it's hard to reach muzzle end of barrel to indicate it, since spindle hole is so long..).

Thanks in advance for your help and Greetings from Italy!

 

[MarinePMI]

Why not set up between centers, and then use a steady rest?

 

[Bill Larson]

Why not set up between centers, and then use a steady rest?

That`s the way to do it..... making sure bore is running concentric.

 

[STR]

Why not set up between centers, and then use a steady rest?

That is the way I started out, and depending on how I feel, and job at hand, I still use it. This will surely start an argument, but before anyone that doesn't agree with it starts throwing stones, please watch the included videos with initial results. I didn't show all the details like cutting threads or using the reamer to chamber. I figured most people already know how to do those parts. The videos were made to prove there are more than one way to chamber a rifle. Hope they help.

https://www.youtube.com/watch?v=epiGY0qFT3Q&feature=c4-overview&list=UUyikBF6Tklx_dP8ENRFhRYg

https://www.youtube.com/watch?v=lnFJl-xSWhA&feature=c4-overview&list=UUyikBF6Tklx_dP8ENRFhRYg

https://www.youtube.com/watch?v=l_MhBOFzoqc&feature=c4-overview&list=UUyikBF6Tklx_dP8ENRFhRYg

 

[MarinePMI]

It's nice to see I'm not the only one that chambers this way.

 

[flatland1]

My lathes both have spindles 21" long, plus the True Bore Alignment System adds another 7"; gotta leave an inch or more of the breech end protruding to chamber & thread, so that essentially means anything shorter than 29" can't be dialed in using the outboard spider. Which is OK, since using SSG's bore rods means I don't need to use the spider to dial in a bbl. When I first started using the TBAS, I was very concerned about having the muzzle end flopping around unsupported inside the spindle. However, it's proved not to be a problem, at least with the bbls I typically use.

At times, when I don't already have the TBAS on the spindle and need to use the spider to dial in a muzzle for brake or suppressor mount, I'll use a dummy receiver on the breech end of a short bbl so it'll reach the spider. I've got dummies made from aluminum & steel, for everything from AR15 & 10 to M700 to Savage small & large shank actions.

 

[colchester]

Overspin you can fit shorter barrels with an "extesion" that will make them long enough to extend through the headstock. You will have to use your imagination and some ingenuity as to how best to accomplish this. Once you have the barrel with the extension installed through the headstock you can indicated the barrel to run true to the lathe spindle bore. You wont be able to indicate bolth ends the way you are currently doing but will take a different approach. Instead indicate a section of the barrel on the chuck side to run concentric to the spindle bore by using a indicating rod and indicating the section that extends from the bore at two points, use the spider and the chuck to adjust. Be sure that the barrel can gimble at the chuck end so you dont put the barrrel in a bind. You can also use a long reach DTI and indicate the barrel at two points by reading directly off the bore. Another method to indicate the bore would be to use a "Gordy rod", if you are not familiar with it here is a link
Barrel Chambering -- Set-Up on Lathe - YouTube

 

[chipsfan]

I run barrels less the 20" between centers, works great

I also do my surefire brakes with the long tenon between centers- I found this is the best way to keep everything concentric

 

[Texar2]

I have an old atlas craftsman and can not run barrels through the center. All of mine have been chambered in a steady rest and the results are amazing. There is an article in the online journal "The Riflemans Journal" where German Salazar visited a respectable rifle builder who used this method. Just google "Remington 40xl" if interested.

 

[ugsly]

I made extensions that I can thread the barrel into and it allows me to use short barrels thru the headstock. Nothing wrong with doing things between center, I just like to go thru the headstock when I can. It makes me feel warm and fuzzy.

Casey

 

[overspin67]

thanks to all there for your helpfulness. I'll try some alternative way, accordingly to your hints and let you know about developments...

Martino from Italy