Metal Lathe for Cutting Rifle Barrels?
- Thread starter oregonboy
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CraigC
Sixgun Nut
I traded a Keltec P32 for an old Logan screw-cutting lathe. By old I mean 60yrs old and mostly worn out. There's really no such thing as a "cheap" lathe large enough for rifle barrels.
Do you think this might work?... http://portland.craigslist.org/clc/ctd/2610673691.html
I would look for an nice old 10 inch South Bend
go to the for sale page here & have a look
http://discoverlivesteam.com/
go to the for sale page here & have a look
http://discoverlivesteam.com/
Jenrick
Member
Define low cost, low cost as in overall not very expensive (couple hundred $). Or low cost for a good lathe (1k-2k)?
-Jenrick
-Jenrick
Ole Humpback
Member
Agreed. This is one question that is super dependent on your machining skills, willingness to go and pickup the machine, and how comfortable you are in restoring a machine that is in less than running order.
First, you need to define what you're looking to machine. This is going to define what you'll look at buying.
Next, you need a very rigid lathe for maintaining accuracy over the length of a barrel plus your stock that is needed to chuck the barrel to begin with. This pretty much means big & heavy (think about 1-2ton+ in weight) machines that will be in the garage on a heavy concrete slab. Also, look at swing over the carriage and bed length. If you're machining a 16" long barrel, you'll need at least 20" between the chuck face & tailstock, so that'd be a bed about 36-48" long. Also, do you want a 3 or 4 jaw chuck? If you want a 4 jaw, how comfy are you with a dial indicator at indicating the material onto the central lathe rotational axis?
Third, you need to evaluate your skills in relation to the machine. I personally need at least an 8spd lathe with a compound post & 4 jaw chuck in order to do what I am able to do on a manual lathe ($8k-$12k new). I would like a 3 gear infinite speed lathe with definable feed rates, metric & english threading gear settings, and an option for a plug in CNC controller for some simple contouring operations ($15k-$25k new). And if you're wanting to flute the barrel, thats going to cost even more because you'll either need a milling machine or a manual third axis on the lathe to cut the flutes. Lets not even get into live spindle tailstocks as I've only seen them on the expensive CNC machines.
Finally, how much money do you have for this machine? If you're looking to buy new or a good quality used machine, regardless of age, its going to cost a mint to buy. If you have the tools & skills to, you can buy some ridiculously good machines for next to nothing because most everyone sees it as a beat to hell machine. The supervisor shop I worked in while in college bought a 48" drop saw that could handle 1" thick blades for $100. It was a **** pile when he bought it, but since he had the tools & skills to rebuild it, all he was out was another $500 to get it running. He spent $50 on raw materials and machined all the parts he needed, $250 on a new motor, and $200 on a couple reels of saw tape for making blades. Another, even better buy, was his metal working saw with integrated blade making tools (welder, grinder, and annealing tool). He got it for free and running for $150. He got it so cheap because someone had knocked it over and broke the cast iron saw table. Again, $75 in raw materials to machine all the needed parts himself and another $75 for TIG filler rods for cast iron.
Its all dependent on what you know and how good you are at turning garbage into gold.
NCsmitty
Member
I have used a 7x12 mini-lathe the past several years to thread mostly Remington centerfire barrels for conversion to small ring Mauser threads. It would seem to me that any standard 10/22 barrel would be easily cut and crowned with a 3"-4" 3 jaw chuck mini-lathe, and a steady-rest, along with a drill chuck attachment for the tailstock to hold the crown tool. You'll need to know how to use the lathe and measuring tools. I had years of machine shop experience prior to my purchase.
Here's a link to some info and reviews on them.
http://www.mini-lathe.com/
NCsmitty
Here's a link to some info and reviews on them.
http://www.mini-lathe.com/
NCsmitty
alemonkey
Member
NCSMitty - I'm contemplating buying a lathe this winter and have been looking at the mini lathes & combo machines. I'm mostly interested in trying my hand at some suppressors (on a Form 1 of course) and maybe small parts like muzzle brakes. If I could chamber, cut and crown full size barrels that would be a plus though. I'm a complete noob at machine tools but it's in my blood (Grandpa was a machinist for Bell Aircraft before joining the Marines in WWII)
Would you be willing to post some more info on the procedures for barrel work on a mini mill? Maybe a separate thread? I do have a good friend who has a complete machine shop in his garage, so I can hopefully turn to him for more guidance.
Would you be willing to post some more info on the procedures for barrel work on a mini mill? Maybe a separate thread? I do have a good friend who has a complete machine shop in his garage, so I can hopefully turn to him for more guidance.
NCsmitty
Member
alemonkey, I really hate typing a long dissertation on procedures, so let me see if I can find a reference link that can help you.
You really need to know basics about measuring with vernier calipers and micrometers, because without that, you're dead in the water on doing precision work.
Mini-lathes can do a lot of things, but you need to have barrels and muzzlebrakes that are .750" or less in diameter to fit through the spindle bore to work them, on most models of mini-lathes.
Mini-mill and lathe combos can be useful, but you cannot hog into work too heavily. A light hand works well.
I'll see if I can locate some information for you, and I will PM it to you.
NCsmitty
You really need to know basics about measuring with vernier calipers and micrometers, because without that, you're dead in the water on doing precision work.
Mini-lathes can do a lot of things, but you need to have barrels and muzzlebrakes that are .750" or less in diameter to fit through the spindle bore to work them, on most models of mini-lathes.
Mini-mill and lathe combos can be useful, but you cannot hog into work too heavily. A light hand works well.
I'll see if I can locate some information for you, and I will PM it to you.
NCsmitty
Ole Humpback
Member
Any of the above mentioned "desktop" or mini lathes & mills would be acceptable for this kind of work. I got the impression you were talking about full blow custom one offing a barrel.
Cutting a barrel to length from the muzzle and crowning it would be easy & safe to do on a mini lathe. That end of the gun isn't a mating surface and nothing really has to fit exactly on it. Heck, if the mill had enough stroke, you could do it on the mill with a dial indicator and a crowning tool. I'd be leary of chambering on the small hobbyist machines though. Its not that you can't do it on those machines, its that if you don't know what your doing and don't know what your chamber tolerances are you could create more problems than you think: chamber not concentric with the bore, the chamber is either too loose or too tight for the cartridge, and my personal favorite the tool deflects off the material and causes a concentric bore at the front of the chamber but is .005" eccentric at the back of the chamber.
Now that last one didn't happen to me on a gun barrel, I was machining a rack housing for a Formula race car and didn't find that one out till I welded the rack housing into the chassis. We figured out what happened when I went to add the oil impregnated bronze bearings so that the rack would float in the housing. It was floating alright, .010" out of place. So out came the reamer and it actually found the line the rack was supposed to be on and all was well, otherwise I'd have to grind out the weld and redo the runout on a lathe with hours of hand polishing to fix it. Don't know if I want to get that kind of surprise with a gun.
Papa_Woody
Member
Shoot I have a 10 lathe my old man used for the very same thing... Staring at it right now as a matter of fact. Wish someone would trade ME a gun for it. Been trying to sell this thing for months
alemonkey
Member
Thanks guys - didn't mean to hijack the OP's thread.
Man, some of you guys are making it sound like cutting and crowning a barrel on an import mini lathe is no big deal. I've been running a 7X14 Homier lathe for a few years and have a 5" 3 jaw chuck on it and I'd never turn anything on it that had to be really centered and straight. I mean, you can start with a fresh piece of stock, turn what you need and have it straight, but to chuck up a barrel in a three jaw chuck, I just don't see how you can get it exactly centered. In know that when I chuck up something that I know is straight and put an indicator on it, the needle looks like it's being driven over a bumpy road.
In any case, my only advise is to do your research and make sure that it's something that you truly need to get into. The cost of the lathe is just the beginning. The cost of the tooling will make your jaw drop; not to mention good calipers, micrometer, dial indicators, a four jaw chuck, or set of collets, etc.
In any case, my only advise is to do your research and make sure that it's something that you truly need to get into. The cost of the lathe is just the beginning. The cost of the tooling will make your jaw drop; not to mention good calipers, micrometer, dial indicators, a four jaw chuck, or set of collets, etc.
madcratebuilder
Member
You use a four jaw chuck. You can indicate as close as your measuring equipment, .0001 is possible. I have a 7X14 and cutting and crowning barrels is not difficult as long as it fits in the through spindle.
I spent many hours improving my 7X14, diy ways, motor and circuit board mods. You have to take very small cuts as lathe well flex, I bolted mine to a piece of 1" thick steel. There are tons of web sites about the 7X?? lathe, lot of info and some incredible items made on them. You can spend more on tooling than the lathe.
I mentioned the thing about the three jaw chuck because NCsmitty said that he does crowns on a mini using a three jaw chuck and that is what the minis come with. My point was that I don't think it can be done with any degree of accuracy with a three jaw chuck. A four jaw chuck would make is doable, but would be an add on and not cheap.
NCsmitty
Member
That's not quite right, I thread barrels with a 3 jaw and a live center. Most barrels are not perfectly straight, and some require a steadyrest to reduce the wobble runout to under .001".
I said that it should be fine to cut and crown a barrel with the basic 3 jaw and a steady rest. I have not had a need to crown a barrel, but I'm confident it would and could be done accurately because it's all in the setup. I have not felt the need to invest in a 4 jaw chuck, because there's more than one way to skin a cat. Sorry cat lovers.
NCsmitty
BrocLuno
Member
You can cut and crown a LOT of barrels at your local machine shop for the price of Lathe? Been there, done that. I still have my lathe, but lordy - how many barrels are you going to re-work?
If making new barrels - that's a whole nuther discussion.
If making new barrels - that's a whole nuther discussion.
BCRider
Member
On selecting a lathe;
For barrel work you need either a head stock which has a large enough center bore to accept the barrels you want to work with OR you need to have enough center to center working distance to hold the barrel between centers.
Generally any lathe long enough between centers to hold a rifle barrel will also have a headstock bore big enough to allow inserting them directly in the headstock. These requirements also eliminates any of the small 7x10, 12, or 14 inch lathes from such use since they have neither the bore size in the headstock nor the center to center distance for rifle barrel work for the most part. To ensure that you can do heavy target barrels it's nice to get a lathe with at LEAST a 1 inch headstock bore. And even that will likely find you holding the odd barrel that won't fit. To get that you're looking at one of the 10x20 or larger lathes.
TonyAngel, when NCSmitty mounts one end in a three jaw and then supports the other end with a live center to do work on the end at the center then the runout in the 3 jaw ceases to be a factor. But you're very right that any work done using only the three jaw to hold a barrel is doomed to failure if a truly accurate muzzle crown is the goal. If a three jaw chuck centers accurately it's good luck and not good planning.
To Oregonboy and alemonkey.... if you've never done work of this sort before you have to start by realizing that you've got a lot of learning to do before you try your first barrel. You're also looking at making up some tooling and accessories for the lathe to allow you to do such a job. Namely a barrel gripper ring for the front to use to hold the barrel in the 4 jaw chuck as well as a 4 finger pot chuck for the outfeed end of the headstock to support the barrel there as well. You'll also require a snug fitting brass insert for the end of the barrel to indicate off for both centering the muzzle as well as checking for axial runout so that the final crown is cut dead on square to the last inch of the bore axis. If that all sounds like Greek to you both then it's a sign of how much you have to learn about metal machining to high tolerances.
For barrel work you need either a head stock which has a large enough center bore to accept the barrels you want to work with OR you need to have enough center to center working distance to hold the barrel between centers.
Generally any lathe long enough between centers to hold a rifle barrel will also have a headstock bore big enough to allow inserting them directly in the headstock. These requirements also eliminates any of the small 7x10, 12, or 14 inch lathes from such use since they have neither the bore size in the headstock nor the center to center distance for rifle barrel work for the most part. To ensure that you can do heavy target barrels it's nice to get a lathe with at LEAST a 1 inch headstock bore. And even that will likely find you holding the odd barrel that won't fit. To get that you're looking at one of the 10x20 or larger lathes.
TonyAngel, when NCSmitty mounts one end in a three jaw and then supports the other end with a live center to do work on the end at the center then the runout in the 3 jaw ceases to be a factor. But you're very right that any work done using only the three jaw to hold a barrel is doomed to failure if a truly accurate muzzle crown is the goal. If a three jaw chuck centers accurately it's good luck and not good planning.
To Oregonboy and alemonkey.... if you've never done work of this sort before you have to start by realizing that you've got a lot of learning to do before you try your first barrel. You're also looking at making up some tooling and accessories for the lathe to allow you to do such a job. Namely a barrel gripper ring for the front to use to hold the barrel in the 4 jaw chuck as well as a 4 finger pot chuck for the outfeed end of the headstock to support the barrel there as well. You'll also require a snug fitting brass insert for the end of the barrel to indicate off for both centering the muzzle as well as checking for axial runout so that the final crown is cut dead on square to the last inch of the bore axis. If that all sounds like Greek to you both then it's a sign of how much you have to learn about metal machining to high tolerances.
win71
Member
- Joined
- Feb 8, 2005
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I would say that for simple work such as cutting and crowning, most any decent small or large lathe with a four jaw chuck would be fine. I would also say that if you start doing that kind of work and enjoy it you'll progress to other more complicated jobs. I was in that position myself.
I found this OLD Atlas lathe. It's close to WWII era. Sears Roebuck sold Atlas' lathes under their store name too. I got this one with several tool holders, tools, steady rest, 3 and 4 jaw chuck, boring bars, drills, live centers, and several other things I have no idea how to use. Price was 725 dollars.
As some have pointed out the headstock spindle diameter on these old lathes and most any other similar lathe is almost without exception smaller than the diameter of a standard barrel blank. Mine is and it was one reason an old gunsmith sold it to me in the first place. This is where the advertised "gunsmith" lathes of Jet, Grizzly, and others have some advantage. For us amateurs it is less stressful to not have to chamber and thread a 30 inch piece of stock way out behind a steady rest.
Like BCRider advised, be careful what you start. I’ve wrecked a bunch of metal trying to recall my high school metal shop days.
I found this OLD Atlas lathe. It's close to WWII era. Sears Roebuck sold Atlas' lathes under their store name too. I got this one with several tool holders, tools, steady rest, 3 and 4 jaw chuck, boring bars, drills, live centers, and several other things I have no idea how to use. Price was 725 dollars.
As some have pointed out the headstock spindle diameter on these old lathes and most any other similar lathe is almost without exception smaller than the diameter of a standard barrel blank. Mine is and it was one reason an old gunsmith sold it to me in the first place. This is where the advertised "gunsmith" lathes of Jet, Grizzly, and others have some advantage. For us amateurs it is less stressful to not have to chamber and thread a 30 inch piece of stock way out behind a steady rest.
Like BCRider advised, be careful what you start. I’ve wrecked a bunch of metal trying to recall my high school metal shop days.
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To the OP, if you're not an experienced machinist or a gunsmith, and all you want this for is to work on 10/22 barrels, I highly suggest you just pay a gunsmith to do what you need/want done.
I was a machinist for many, many years, and I can tell you firsthand that while it's fun and satsifying, it's also very expensive and frustrating. Tooling is incredibly expensive, and it breaks very easily. Making mistakes and breaking things on someone else's dime is one thing, when it's YOUR dime it's a whole 'nuther story.
I really enjoyed being a machinist and would love to have that ability at my fingertips again, but it's really not for everyone. Ain't something you can just go buy a lathe and get started doing. Lathes break things with great gusto, and very quickly.
I was a machinist for many, many years, and I can tell you firsthand that while it's fun and satsifying, it's also very expensive and frustrating. Tooling is incredibly expensive, and it breaks very easily. Making mistakes and breaking things on someone else's dime is one thing, when it's YOUR dime it's a whole 'nuther story.
I really enjoyed being a machinist and would love to have that ability at my fingertips again, but it's really not for everyone. Ain't something you can just go buy a lathe and get started doing. Lathes break things with great gusto, and very quickly.
SleazyRider
Member
Fred Flintstone method ...
Not sure of the "correct" method of re-crowning, but I begin by turning a snug-fitting aluminum slug that fits into the bore, and after inserting it an few inches, indicate it on the 4-jaw for concentricity with the bore. ( If the barrel is tapered, I turn 2 aluminum donuts that I slice in half with band saw to maintain parallelity with the jaws of the chuck.) I then cut the crown from the center out.
I understand crown cutters are available to perform this using the bore as a pilot, but I'm too cheap to buy one.
Not sure of the "correct" method of re-crowning, but I begin by turning a snug-fitting aluminum slug that fits into the bore, and after inserting it an few inches, indicate it on the 4-jaw for concentricity with the bore. ( If the barrel is tapered, I turn 2 aluminum donuts that I slice in half with band saw to maintain parallelity with the jaws of the chuck.) I then cut the crown from the center out.
I understand crown cutters are available to perform this using the bore as a pilot, but I'm too cheap to buy one.
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