Smallest lathe for chambering, threading and crowning
OK - I know that the smallest lathes probably isn't the best for the job, however all I want to do is to chamber barrels, crown and re-crown them and of course thread them.
What is the "smallest one" that could do a proper job? I can add that this is for 6ppc barrels only.
What spec do I need to look for in order to find a proper lathe for the job?
Any input or help is greatly appreciated since I consider myself a freshman on the area.
HopeToBe, I don`t think you would bring a riding lawnmower to the grand prix, so do yourself a favor and buy a real machine. The proper lathe will be the built like a tank, heavy and able to do the job well. To quickly answer you question, you need a spindle bore that has a minimum of 1.3" or so, and have the ability to cut different thread pitches. I have a 12x36 Grizzly G4003, and it will only handle short barrels 20-21" through the headstock with a custom spiderchuck on both ends of the spindle. I recomend finding a rigger (heavy machine mover) in your area. Talk to him about where to find a machine. He will be a good rescorce.
Last edited by varminthunter1; 05-17-2011 at 05:18 PM.
Yo Jeff, are you Gordying your stuff?
Originally Posted by varminthunter1
No, I use PTG indicator rods on breach, check run-out with test mic on short chamber.
For chambering, threading and crowning you only need a 12" bed as long as you can get the barrel into the headstock. Too bad most "second operation lathes" don't have threading capability, or they would be perfect for 99% of gunsmithing work. I posted thread on this forum a few months ago about a lathe coming out with a large hole in the headstock to accept just about any barrel you will be working on in the gunsmithing trade. And it was relatively inexpensive.
I use a Jet BD (belt drive) 12 X 36.......A couple times I thought about "upgrading" to something nicer, but this lathe is extremely accurate and the headstock is short enough where I can easily work on a 20" barrel with one end in a spider and the other in a huge 6 Jaw Bison Tru-Adjust chuck.
Gunsmithing just doesn't require the absolute precision that some folks convince themselves is necessary. And it certainly doesn't require 5000 pound engine lathes. Lots of records have been made with simple South Bend Model 9 lathes and Grizzly imported machines.
Hope this helps..............Good luck!
You also might look at the Smithy line. I own a Granite Classic 1324 and can do any gunsmithing operations on it, spindle bore is only 1.125" so the largest barrel I can chamber is a 1.100" to allow adjustment of the spider I made for the rear. Another advantage is you have a mill attached that is also needed many times in gunsmithing. I don't think the cost is much more so you should consider the 1340, a bit bigger. You do have to change belt locations for the three speed ranges but I have not found that to be a problem. The one real advantage that I have found is the Variable Speed Control, the low range goes from 0 to 400 so when running a chamber ream in say 30 to 70 RPM and you here some chatter you can instantly change speed by just a slight turn of the control, something you can't do on a gear driven system. Even though these are smaller machines the low range has plenty of power.
and yes I know it' made in CHINA but remember ( A good machinist can do good work on a crappy machine once he learns the machine.) Good Luck
What you are looking for is a lathe with:
Originally Posted by HopeToBe
1-1/2" spindle bore
no more than 19" or 20" or so from the back of the spindle to the front of the 4J chuck.
Minimum spindle speed between 35 and 70 rpm. I'd regard 70 rpm as the highest acceptable minimum spindle speed. 35 is much better.
Quick change gear box and change gears to do both inch and metric threads
threading dial for at least inch threads
carriage with both cross slide and compound
Aloris type quick change tool holder
I personally prefer at least 36" between centers because that makes it possible to polish a barrel by spinning it between centers.
What does this translate to? South Bend Heavy 10 (which only has 1-3/8" through the spindle) or about any well made 12" x 36" import. Grizzly, Jet, Victor (probably the best of the three) are typical examples.
You can do what you need to with a small lathe with 36 inch centers and a steady rest... I did for many years... but some things are considerably slower and more difficult.
I would recommend a short headstock and at least a 1.375" hole and 36 inch centers. I have an 11 inch Rockwell made in the early 70's and it is great.
Last edited by Dennis Sorensen; 06-07-2011 at 06:26 PM.
Reason: added info
If you've ever seen a Southbend Heavy 10, they don't come much smaller than that and have probably had more benchrest barrels chambered on them, than just about any other lathe.
Anyone have any experience with the Clausing 11"?
I'm an accounting/financial guy. Let's start with the most important aspect of this project.
What's the top end of your budget?
That's the same lathe I used in high school. Wish I could find one locally to buy.
Originally Posted by Dennis Sorensen
The Rockwell is an excellent barreling lathe.
A slightly contrary opinion - the lathe itself is seconday. Any machine with a long enough bed (42") or a big hole (1 1/2") thru the headstock, that has good bearings and decent ways, will do the job for you. What is most important, IMHO, is 1), your ability and 2), the tooling, which will cost you more than you will pay for most lathes.
Money isn't really the issue here, space is. I could say that my limit is $10000, however I would not hope to go there. And I am not doing this to save money chambering my own barrels, this is for pure interest being a competitive benchrest shooter.
Originally Posted by abintx
The other thing I have in mind is that if I buy a big lathe that is able to do a lot more than my initial thoughts on this subject I am afraid that this might exaggerate slightly...