Metal Lathe for Cutting Rifle Barrels?

[BCRider]

Rondog raises a very good point. If you're looking to get into machining as a hobby which covers more than just gunsmithing or you plan on doing a LOT of gunsmith machining then great. But be warned that the machine is only the thin edge of the wedge. Your pocket book will eventually be pried open to dump out about as much again as the cost of the lathe for tooling that you'll need which can be related to the lathe directly or to support hand tools to go with the lathe working.

 

[husker]

I agree with What BCRider & a few others said. If you shop around you can find very very nice old laths,that are better machines that what you find now at Grizzly ect. But the big plus? Most if not all the Tooling will be offered with or in the sale of the lathe

 

[dusty14u]

For bigger barrels I prefer a larger sized lathe. Our largest lathe in our shop



Just joking guys. As rondog mentioned a decent lathe is just the start of the outlay. Tooling is where you will have your money tied up. Decent lathes can be had at commercial auctions but most of them need fixing or tooling. If I was getting a lathe I would get a collet chuck and a 4-jaw. Some high dollar 3-jaw chucks come with micro-adjustment screws and act much like a 4 jaw.

Measuring instruments are a big outlay in cash also. I use tenth indicators for close dial ins and have mics from 0-1 to 11-12 as well as a Kennedy roll around crammed with all other measuring instuments.

Once you get your lathe you will also most likely need to get your garage wired for 220 service, which might be an added expense. I wired my garage so I could put machining tools in if I ever decided to do that.

 

[BCRider]

On buying a used lathe. One major consideration is to know what to look for on the beds for wear issues. A lathe that was used for a lot of abrasive work such as tool post grinding or where the operator used a lot of sandpaper for polishing and didn't cover the bed will likely be worn "swayback" in the most used area close in to the chuck. Some scratches and dings are all fine but signs of such wear mean that doing truly accurate work with the machine isn't going to happen unless you get the bedways re-ground. A rather costly option.

You can test this if you have a good quality 12 inch heavy machinist's scale (ruler) or set up straight edge. Just lay it lengthways on the bed and see if you can slip a .002 feeler guage easily under the ruler at mid point. If you can then the bed is worn beyond what I'd pay for.

It also suggests that when you're using your own machine that you should ALWAYS cover the bed when using abrasives. Cloth can get sucked up and fly around in the chuck or work. A sheet of cheap oiled thin leather will lay limp and "dead" on the bed far better and being heavier won't tend to get sucked up by any breezes. Otherwise at the very least run the carraige back out of the way, use your abrasives and then CLEAN the bed well with rags and solvent before re-oiling and using it normally. It sounds like a lot of trouble but over the years it'll save the lathe bed and ensure you continue to do accurate work.

 

[dirtyjim]

i've threaded a lot of barrels on a grizzly 9x19, same lathe as most other import 9x20's.
if your buying new wholesale tool even offers it with a 48" bed for not much more money.
i reamed the spindle to .814 to fit larger barrels through the headstock & made a rear spider from a plumbing fitting.
its not a good picture but here is the barrel from my 375 H&H being threaded, its about as big as i can go in a 9x20 lathe.


homebuilt spider that is held onto the spindle with 4 set screws.


right now i'm doing a dc motor conversion so i can change speeds with the turn of a knob instead of having to change belt positions.
as they come the slowest speed is to fast to thread to a shoulder so i do most of my threading towards the tailstock with the lathe in reverse.

 

[bgr2014]

Gunsmith Lathe

Another good place to find what you need is Smithy, they have all the accessories you need and have good customer service. I've tried the used lathe route and finally bought new lathe and mill from them. Very satisfied with how they have done for me for over 14yrs. and they are still like new. Mine is 13X48 with a 1 3/4" spindle hole. I made a 3 point chuck for the headstock for holding barrels and barreled actions. I use an indicator and wiggler on the inside of the bore when cutting a crown or threadind for a muzzlebreak. The bore and outside of the barrels don't run true. Have been a machinist since 1960 and doing gunwork almost that long. Open your pocket book and start out right. Good Luck

 

[Ole Humpback]

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.

I take it that you don't have a self centering 3 Jaw chuck? Even if its not a self centering 3-jaw, you can still indicate it in like a 4 jaw chuck. There should be 4 allen screws at 90 degree intervals around the chuck itself on the outer diameter. Just indicate as if you were using a 4 jaw chuck and it'll be as good as gold. Plus, you'll be able to eliminate runout with a 3 jaw far easier than a 4 jaw.

 

[BCRider]

TonyAngel, the trouble is that you're not using the right setup. For centering any existing workpiece you do NOT rely on the three jaw that came with the machine. Three jaw self centering chucks have far too much play to accurately center a piece. Very typically they'll have from 5 to 20 thou of runout. That's why you're finding what you found.

If you want to center up something be it a pin or a barrel you have to use a 4 jaw independent adjustment chuck along with a dial guage. You use the dial guage to indicate the work piece for runout. Then you adjust the 4 independant jaws until you zero out the workpiece. With practice it can be done as quickly as you read this description. At first though you're like to pull out most of your hair....

My setup for doing this is a dial guage with a mount on it that fits into my tool post such that the dial gauge feeler is right at the centerline. I then zero out two opposing jaws first then do the other two at 90 then come back to the first two. It takes two or three times back and forth but with a bit of practice you can zero a workpiece to less than one thou in a couple of minutes or less.

Humpback on any of the little table top lathes I seriously doubt that they come with a Tru-Set style chuck. It's far more likely that he's just running afoul of the usual lousy centering found in most cheap 3jaw self centering chucks.