Lathes for Molds

[30yrcaster]

What types of CNC lathes would work for making bullet molds on the smaller scale? Any of the CNC mini lathes or do you need the big professional quality stuff with coolant etc?

Thanks!!

[44man]

I use a cheap Smithy mill, drill, lathe to cut cherries and make moulds. I think any CNC machine would be a step up.
I think the problem with your question is that most of us can't afford one and only the experienced machinest will be able to answer it.

[Buckshot]

..................If you're gong to go the pro route via CNC there are several options. Lee uses a CNC lathe with a rotary toolhead, but I don't know how many positions. Dan at Mountain Moulds has a CNC setup. I don't know how he handles the tools. His software he has for you to design a boolit on is geared to a number of 'set' tools. That way he doesn't have 20 tools used all the time and 187 tools used once or twice.

But for CNC to be effective your tools have to be zeroed and repeatably removed and replaced unless you have a rotary toolhead. The toolhead retracts and rotates via the program to present the next tool. The previous way with tool holders is the tool retracts and then goes into a hold position so you can remove the toolholder and replace it with the next, then tell it to go again.

The size of the lathe would be determined by the size and material your blocks will be. If you just did single cavities in aluminum all you'd need was maybe a lathe to swing 4" as you have to count some means of holding the blocks. If you plan on 4 cavities then you're probably looking at a 12" swing (or so).

In addition to the tool holder setup for boring, you have to have a fixture to hold the blocks that is consistant and easily setup. You have to decide whether you're going to leave it in place and remove and replace blocks, or remove the fixture itself.

..................Buckshot

[30yrcaster]

I think the problem with your question is that most of us can't afford one and only the experienced machinest will be able to answer it.
I thought some machinists would chime in on this one as they would know what the min would be to make it work for a home setup.

It's funny when you post a question on some of the machine shop forums about small lathes or mills, you get 20 responses from machinists telling you to get a huge Bridgeport mill that weighs 1500 lbs and costs 10k.

I thought for lathe boring out a mold, it's only a hole with some grooves in it. Thought that would be pretty simple for CNC. Thought it would be even simplier to make a paper patch bullet mold that doesn't even have the grooves.

[44man]

The problem is that anything with CNC in front of it is not cheap. Kind of defeats making your own moulds unless you are going into business or have a lot of money to play with.

[Bent Ramrod]

30Yr,

The main advantage to CNC is reduction in labor costs over a very large run of items. The machines, the programming and the tools are very expensive at the outset and are only amortised by not having to pay a skilled workforce for mere production work. Remember the programming starts the machine at a zero point so even sharpening the tools will change dimensions unless they are sharpened extremely accurately and the slight reduction in size is taken into account in the programming.

When you say, "on the smaller scale," I presume you are just thinking of making an experimental mold or two rather than even short production runs. CNC offers absolutely nothing but vast costs and complications for "onesy-twosey" work like this. I would submit that the "minimum" you are working for is a lathe with a 4-jaw chuck, dial indicators for centering and travel measurement, and a set of twist drills, a reamer or two and some hand-ground boring tools to cut grooves and ogives.

Machinists who are pros automatically talk in terms of big machines and big tooling investments, because that's the way their workplace is set up for maximum cost-effectiveness. You need to talk to the retired ones with a self-purchased shops in their basements, or the home shop amateurs, with similarly limited means.

[PatMarlin]

Does anyone know where you can see the process of machining a mold on the net?

I've never seen the process.

[Buckshot]

.............30yrcaster, let me say first of all I do not know your machining experience. I am NOT the old man of the machine shop with years of experience under my belt (we do have a few here on the board though) like Kenhuudo or Willbird to name a couple. I hate to come off like I'm talking down (unintentional). I have only had my lathe for the past year and a half. It has been a life long dream and so I have been a bit whacked out about it to the point that some people I know will hide if they see me :-)

It's so bad I cannot understand how anyone could NOT want to have a lathe. At least a guy! I have become a disciple of machining. I would sit at work on the net and pour over umpity bazillion pages of old threads from the Practical Machinist and the Home Shop Machinists BB to name just 2, but there are more. I know I've spent over $200 on just books about machining, it's practices, theories, the tools, setups, and how things can be done.

And that is the main thing about machining. How to go about something. How to set it up, the steps and the sequences involved. A guy like me with a manual machine really doesn't need to read anything printed after 1938. The big thing I've learned is that it isn't rocket science. It's a lot of common sense, some patience (which I've had to come to grips with) and maybe even a bit of intuitiveness. The next is learning your machine.

I think it's a bit like being a sculpturer. You machine away everything that doesn't look like what you want to end up with.

When I first read about cutting mould cavities on a lathe, vs a cherry in a milling machine, I kind of had an idea of how it was done. Wasn't too many ways it COULD be done :-) One way for shorter fatter cavities is with a form tool and the other way (which works for most anything) is single pointing using multiple tools to do the carving.

I hate to sound like I'm tooting my own horn here, but I've been very pleased and excited about many of the things I've accomplished in a fairly short time. Most of it came about by having the process kind of just drift through my head (and a lot drifts through and just keeps on going, too!)

http://www.fototime.com/129DCEECEED65CD/standard.jpg

I have a swage press and decided rather then pay $280+ for a couple swage dies I'd make my own. This is also kind of like using a form tool to cut a mould cavity, although this tool is very simple, it IS a form tool. A piece of high speed steel ground to the shape desired, then presented to the workpiece to bore a facsimili of itself.

http://www.fototime.com/B35265B203A27EA/standard.jpghttp://www.fototime.com/7BAE9A1545DD0FC/standard.jpg

And the result is above. Of course it's swaging and not casting. However the similarities are you put in something on the left and the result is somehting different on the right. So instead of one piece you use 2 blocks and bore the hole, add sprueplate and convert wheel weights into boolits.

http://www.fototime.com/B14C8C7293C3501/standard.jpg

This is kind of an example of single pointing. You still use a form tool ground for the purpose of creating a particular feature in the cavity. In this case it was drive bands in a 12 guage slug mould. You grind the tool(s) you need to create a particular boolit design, then place them in holders. They all have to be zeroed to a reference point because you're working where you cannot see. You have to either have a digital readout, or setup dial indicators on the axis you're going to be operating on, or have a CNC machine and know how to write code for it.

In the case of the mould above, I screwed it up by not thinking it through. According to the guy I did the work for it's fine, but it wasn't what he asked for. He wanted 3 drive bands. I failed to figure in the width of the single pointing tool when I advanced it for the next cut. I realized what was going only after making my third cut. I was pretty sick, lemme tell you. I spent a bunch of time drawing out the dimensions on a tablet and then retracing my steps to figure out where I was and what I'd done to that point. Remember, you can't see inside the cavity! I figured I could cut one more drive band to at least have it LOOK okay, ha!

CNC is a wonderfull thing. It's a great production tool and it lives in the arena of outfits that makea bunch of one thing. It has it's pitfalls too. In one sense it's simple, but in another it is extremely complicated. Guys who can write and interpret code are usually well paid. Then you might also have toolsetters who setup the various tools. And setup is the most important part of any machine operation. Crappy setup nets a bunch of crappy parts regardless how good the machine is.

But back to moulds. You can checkout Starmetal's work over on the Special projects forum. He's made a couple pistol boolit moulds of TC design using a form tool. He has one of the small 7" lathes and he made his own fixtures to hold the blocks, turned, ground and stoned his own tools to cut the cavities. One was a single cavity and then he turned around and made a 3 cavity. Thing is he's only owned the lathe for maybe 6 months. Then he made gas check blanking and cupping tools.

So..............

"I thought some machinists would chime in on this one as they would know what the min would be to make it work for a home setup."

Nobody really can unless they know what you have available and what you plan on doing. As I mentioned, Starmetal has a 7" import manual lathe that cost less then $600 and he's had it maybe 6 months, but he's making boolit moulds.

Dave Farmer of Hoch moulds uses a Hardinge 2nd operation lathe (like $20,000 worth, not counting tooling) especially set up for cutting moulds and he also uses form and single point tools.

If you look at the cover of the current Lee catalog you'll see a guy leaning on their new CNC lathe with it's rotary toolholder. I have no idea what that hummer cost, but I'd imagine it was close to 6 digits. Program it, tool it up, close the cover and mash the green button. You just stand there and pick your nose until it's time to change workpieces.

[PatMarlin]

I have only had my lathe for the past year and a half. It has been a life long dream and so I have been a bit whacked out about it to the point that some people I know will hide if they see me :-)

It's so bad I cannot understand how anyone could NOT want to have a lathe. At least a guy! I have become a disciple of machining. I would sit at work on the net and pour over umpity bazillion pages of old threads from the Practical Machinist and the Home Shop Machinists BB to name just 2, but there are more. I know I've spent over $200 on just books about machining, it's practices, theories, the tools, setups, and how things can be done.

These are all the signs of a great artist in the making.. :drinks:

[StarMetal]

Buckshot,

First I wanted to post this picture, it's the picture of the machine shop on my Destroyer. It's what got me interested in lathes many many years ago and it WAS many years after that I got that little mini lathe.

They make a CNC setup for mini lathes and I guess it's expensive. Like Buckshot said CNC is only good as it's setup is good. Like he said you will turn out alot of junk. I think an important thing is to have the will to really want to make something and make it right and good. I find myself spending more time on my lathe then with my guns now. Get all the books you can, read alot about lathes and stuff on the internet , and ask alot of questions to someone that's a decent machinist or at least someone that has more experience then yourself. Never be ashamed to ask questions. I call Buckshot alot and ask him questions. As Buckshot mentiones I make alot of my own fixtures, grind my own special form cutting tools and stuff because I really don't have a budget to just go out and buy all the stuff I need. I think sometimes I make Buckshots eyebrows go up. I hadn't messed with a lathe in like 40 years and I buy that mini lathe and in the first month I had it, I made a 30 luger barrel for a 1911 Colt by using liner made from a turned down 30-06 barrel and lining an unfinished 1911 barrel that was drilled and reamed to be a 45acp, but never rifled. I know Buckshot was just amazed that I done that so quickly after receiving my lathe and virtually no experience. I just had this strong determination to do it.

Here's that Destroyer machine shop Buckshot.
Joe

[Frank46]

Joe, kinda brings back memories when I was on the swanky franky. Our machine chop on board ship wasn't that much bigger. One machinest spent about 6 months making boiler feed pump shafts out of railroad box car axels. If you ever had a boiler feed pump runaway on you, then you can usually kiss the shaft goodbye. When that happens, jam the wedge to hold the poppet valve closed and run like heck. Thanks for the memories. Frank

[44man]

I never used a lathe before and the only book I have is the manual that came with my Smithy. It is really a junk machine, but I make it work. Play in the adjustments makes it almost impossible to bore a mould and is the reason I chose cherries. Even those have to be snuck up on.
I have a lot of respect for Joe and what he has done with his machine. He is a nice guy and smart even though we dicker in fun a lot.
I would listen to the guys and just get a decent used lathe and use your head a little instead of looking for an easy way out. Yes, you will mess up a lot, but each is a learning experience. Just look back and see what the old gunsmiths did with a water wheel. I can't begin to do what they did. Each and every day, my respect grows when I see what was done a long time ago. I feel dumbed down something awful.
I read about a gunsmith with a water wheel that was able to devise a way to rifle a barrel completely while he was sleeping. Come on guys, how many of us are really smart?

[StarMetal]

44man,

Thanks for the kind words.


Frank,

Us boilermen use to like getting the machinist mates going by cranking open the check valve on the boiler water feed and hear the feed pump back in the engine room start to take off. Then we'd get a call from them ******** at us, but we done cut it back some by then.

Yeah that machineshop was so small I believe if you left a good fart it would rupture everyones eardrums.[smilie=1:

Joe

[crazy mark]

On the Cutter I was on there was only 2 of us that had lathe experience below the rank of chief. Me a BT and a MM. We made a lot of valve stems with acme screws. We had piston electric feed pumps so not much to make there and of course all sorts of widgets for officers and chiefs. We had a good size machine shop amidships in front of the boiler room. Mark

[Bent Ramrod]

The Smithy might have a lot of compromises built into it in order to do all the tasks it is able to do, but it is far from junk. A friend of mine does a lot of small-to medium scale gun work on his. My own shop has two Atlas lathes and an Atlas shaper, complete with the notorious pot-metal gear trains and flat non-precision bedways. I don't expect to be able to pull a 1/10" chip off a piece of metal and still maintain a tolerance of + or - 0.0001", but if I take the time, make light cuts, and am careful, I can still do good work on them. A production or toolroom machinist simply couldn't afford to take the time that the hobbyist can take and still keep his job.

I started out with a Unimat, and was delighted with what it could do. Of course, I couldn't afford a gunsmith to fix up all the wrecks I was hauling home from gun shows, so anything I could do myself was all to the good.

It's a bad mistake to think that you have to have a squillionth of an inch precision built into the machine in order to even start. An operator who knows his machine can do amazing work, even if it is worn or lacking in rigidity.

I would recommend that anyone interested look up their local community college and see if they have machine shop courses. You can get a good idea of the potential, see if your interest maintains itself, and even make some interesting stuff, with only a minor outlay for tuition.

As Buckshot says, once you get into this machine work, you wonder how you ever managed without the machine tools. Kind of like pickup trucks in that respect.

[44man]

The Smithy can do a lot when care is used and time taken. The first thing I had to do when I got it was to just about take the whole machine apart. All the bearings were full of cast iron dust and had to be washed and re-packed. I removed as much play and backlash that I could without binding things up. I have to constantly adjust gibs as I work.

[KTN]

Couldn´t wait any longer,I just got to try it.Here´s my first try on boolit mold making,and naturally,I managed to mess it up:( .As you can see,boolits nose is deformed because I drilled pilot hole too deep[smilie=1: .I need a LOT more experience with these things,but I will get there.On top is form tool I made to cut cavity.Next time I will try to make FN mold.It isn´t so difficult and yes,it is addictive. (don´t tell ATF):mrgreen:


Kaj

[StarMetal]

Hey KTN,

That's not bad pardner. The cavity looks good, except for the pilot hole you pointed out. When I drill my pilot I drill it a few thousandths of an inch short and let my form tool bore the rest. Another mention are your guide pins. The ones you have will work, but eventually they will wear the aluminum hole out. On mine I use a steel sleeve for the hole.

Excellent first try.

Joe

[KTN]

Starmetal,thank you.I have been reading your posts about mold making with great interest,and I agree about those guide pins.Since this was my first try,I just skipped steel sleeves for guide pins(I just wanted to make it fast to see if I CAN make a mold).On my next mold,I will use those sleeves.


Kaj

[StarMetal]

KTN

I'm sure you know this, but just to be safe I'll mention it. Put your alignment pins in before cutting the cavity. That way there won't be an alignment issue. Sometimes it's easy to overlook the procedure sequence. Make your sleeve and pin a diameter that will assure a very tight press fit too. That means having the correct drill size.

Good luck.

Joe

[Buckshot]

.............KTN, very impressive (the sound of applause!). The cavity looks very smooth and well finished. That little dimple on the nose won't make any diference at all. Think up some catchy name for it. Or you could always hollowpoint those blocks and do away with the dimple altogether.

I don't know if there are any mold makers up in your neck of the woods, but here is a golden opportunity for your lathe to pay for some of it's tooling! You've already made a lube-size die, so now you can try a push through die, and custom nose punches too!

Heck, pretty soon you'll be rich. You buy the beer and we can all come over and hang around in your jacuzzy :-)

................Buckshot

[KTN]

Starmetal,
thanks again for reminding me about those obvious points that are so easy to forget,like drilling too deep pilothole[smilie=1: .

Thank you Buckshot,I´m VERY pleased with my first try on mold making.I was also thinking about hollowpointing these blocks,but then I decided to save them as they are,and put them on my loading bench to remind me about my mistake.I haven´t heard of anyone making molds here,at least not commercially.I have asked few of my machinist friends about mold making,and they have all said it´s too difficult (and they have big and expensive CNC machines) just can´t wait to show them my molds:twisted:
About those tools and their cost,now I REALLY want that milling machine and all the other machining stuff.Looks like it´s going to be bread and water on the menu for the next few months:) Luckily,one of my shooting buddies is toolsharpener (is that right word?),so maybe I can get some tools from him. (Company he is working for makes some tools for Sako:mrgreen: )So far I have been lucky to find some of my tools and materials cheaply and even free,like 20 ft of high speed steel for toolmaking and 3 ft of 1"x2" aluminium for free.
Me being rich?That would never happen,and closest thing to jacuzzy I will ever have,is hole sawed on a lake ice.From sauna to icehole,that would be COOL.It also keeps your beer cold,and jacuzzy can´t do that.


Kaj

[StarMetal]

KTN

Your first mould a failure? NOOoooooo I don't see it that way. It's definately useable. I found the hardess part is to cut the cavity to the correct size. Second hardess is hardening a cutting tool hard enough.
I have quite a collection of moulds I made now from all my mistakes [smilie=1:

I like that jacuzzi idea of your, a hole in the ice in the lake. hahahahahahahaha

Joe

[PatMarlin]

I think the mold should be sent to me Kaj. That would releave any aspect of unhappyness you may have with it, and you will feel much better knowing it's going to a very good home.. :mrgreen:

[Bent Ramrod]

KTN,

Excellent job on that profile cutter. The mold itself is a very good first try. If you pick the proper top punch, that little peak on top of your castings should disappear as they come out of your sizer.

[13Echo]

Keep the peak! You could start a trend; The reverse hollow point! The latest thing in cast bullets. Soon everyone will want one, Lyman, SAECO, Lee, and RCBS will be falling all over themselves to bring out moulds. The custom makers are probably already making cherries and programming CNC machines with new designs. Heck they're probably buying new tooling just to keep up with the expected demand! You have just revolutionized the cast bullet business!

Jerry Liles

[PatMarlin]

I cann't find Joe's molds. Could someone post a link? Thanks.. :drinks:

[30yrcaster]

.............30yrcaster, let me say first of all I do not know your machining experience.
...
When I first read about cutting mould cavities on a lathe, vs a cherry in a milling machine, I kind of had an idea of how it was done. Wasn't too many ways it COULD be done :-)
...
I have a swage press and decided rather then pay $280+ for a couple swage dies I'd make my own.

Gee Buckshot,

We seem to have some of the same ideas here. The Rigby and the lathe boring.

Sorry, I'm not a machinist but a broken down mechanic turned software engineer wishing I had the space for a variety of machine tools. I've been fabricating parts for a long time unfortunately not with the tools that make it easy.

I've been swaging bullets since the mid 80's with Corbin & RCE equipment. Using swaged paper patched bullets with the muzzle loaders, there's a multitude of diameters you may want within a given caliber based on the bullet weight, paper thickness and bore dia. If you order a swage die from either Corbin or RCE you can expect to wait 6 months to a year to get one and pay $300 each and it's a crapshoot if it will actually be the dia you asked for. If you find you want it a couple thousands larger or smaller, you have to wait another 6 months to a year. By that time you may die from old age or most likely loose interest.

I thought lathe boring would be the way to go with a small lathe. The CNC part I thought would handle cutting the radius easy and to make it a couple thousands larger or smaller just change the pgm a bit and run off another. I wasn't looking at CNC for running off hundreds of parts but to ease in modfying the die for a different but similar design and cutting the radius on the nose.

[StarMetal]

KTN,

How are you measure your band widths when cutting the cavity?

Pat Marlin

My thread is in the mould maintenance and repair section under ATTENTIONIE DEPUTY AL 30 LUGER.

Joe

[PatMarlin]

Thanks Joe.

How in the heeek can Corbin stay in business like that?... :confused:

[StarMetal]

Pat,

Because it's alot alot alot of work to make these things on a lathe. That's the reason I haven't been making gascheck tools for members. If I could just set up, cut, reamer, etc., in a reasonable amount of time with a minimum amount of efford I'd be burning those things out. Do you think Dan at Mtn Mould would be making and selling moulds if he didn't have a dedicated machine to do so? Nope. With CNC you have to have an accurate lathe, for an example, to use it in my opinion. Then once you've got it programed and tools are ground correctly, it would be faster with less effort. Set up time on any machine is very time consuming too.

I believe you are getting a fair price on Corbin products, but like I said they are too expensive for my blood.

Joe

[KTN]

Pat,
thanks for the offer,but I still keep it as reminder.(You know,SOME people only learn from their mistakes[smilie=1: )

Starmetal,
on these first molds,I have carefully measured diameter with a caliper and cut very slowly (while keeping my fingers crossed and hoping for best).I´m going to buy digital measuring devices for my lathe in near future.If I keep making molds like these two first,pretty soon I´m going to have bigger collection of "mistake" molds than you.:mrgreen:


Kaj

[30yrcaster]

Thanks Joe.

How in the heeek can Corbin stay in business like that?... :confused:



I believe you are getting a fair price on Corbin products, but like I said they are too expensive for my blood.

Corbin can stay in business because alot of guys want to make their own bullets but don't want to spend a fortune. He doesn't tell you the entire cost of doing it. There's extras you don't know about until you start doing it.

The dies most bench rest guys use that are still being made are Niemi. (there may be others but he's a big name) They are made out of carbide and will last a lifetime. Their cost is $3500 and you'll wait about 3 months. Corbin says his dies are bench rest quality but I've never seen them mentioned by winners of BR matches. Niemi, Detsch (no longer made but sought after) and others. Corbin dies cost about $400 for a 3 die set but they're hardened steel, not carbide. He'll argue you will never wear them out but I've heard of many that have. This is for jacketed bullets. There aren't alot of people around that make this equipment so he and his brother at RCE are about the only game in town if you don't want to spend the $3500. Also he makes custom calibers and it's all done by hand, non CNC unless he's upgraded.

His prices are fair and I've never complained about that just that he makes you wait forever. You also have to be careful when you order stuff from him. He doesn't disclose everything you need to end up with your final bullets. He talked me into buying a gallon of his dip lube also called "liquid jackets" for swaged pistol bullets. Guess what it scrapes off when you load them and when I told him I was getting sprayed in the face with lead with my revolver he told me his lube wasn't the best thing out there and I needed to buy a knurling or cannalure tool. Another $80. When I got the knurling tool the doc mentions it's only for testing purposes and not for large quantities, you'll wear it out. You really need a power tool made for that. When you add it all up it's hundreds more than what you started with. Chances are if you knew the entire cost you'd never get into it.

He wanted to sell me jacket reducing dies so he could sell me his jackets that were the wrong size. After talking to his brother at RCE he told me to buy the jackets from Berger as they were already the size I needed. Why would I want to do the extra steps in reducing jackets (less accurate as well) when they are already available and spend hundreds for extra dies?

The rebated boattail design sucks. All his doc says how it's the most accurate but it's really only for manufacturing purposes. It's difficult to make a boattail bullet as the punches will fly apart thus needing the rebated design. The only one selling them any more is Lapua and they aren't their premier bullets. They are FMJ from 1930's technology. Probablly the best FMJ bullets out there but not the most accurate. I could go on and on about this but I'll spare everyone.

You'll get more reliable info from RCE but you'll still wait for a long time go get your equipment. Like many gunsmiths, they'll tell you 3 months and deliver 6 months to a year later. Richard Corbin (RCE) is a really decent guy to talk to and won't rip you off.

[StarMetal]

KTN,

I started with using a dial indicator on the crossfeed table. That wasn't good enough so I bought me an dial indicator bore measuring tool and that is much much better. I found that I could stop cutting and back my tool out and measure and then put the tool back in the exact location again. So this is working for me.

Joe

[Buckshot]

..............30yrcaster, I bought a Walnut Hill swage press, dies and core mould from Richard to swage .443" diameter cup based based slugs for paper patching in the Whitworth and Rigby.

http://www.fototime.com/843853136AD317F/standard.jpg
http://www.fototime.com/F5B2831828DBFE3/standard.jpg

After getting a real live lathe that does stuff :-) I began making my own swaging dies.

http://www.fototime.com/C3EE3AD183E490A/standard.jpghttp://www.fototime.com/86928C1813B4A70/standard.jpg

I've made 3 dies sets for making .575, .583 and .596" Minie' bullets, and another for hollowpointing or hollowbasing 38 cal slugs and bumping them up to .363" for use in a couple 38 S&W revolters.

http://www.fototime.com/7CA2B3C3EC5D49E/standard.jpg

The above is a reloading press type swage die I made for making 45 cal HBWC's or SWC's.

And you're right about Richard Corbin. He's a fine guy and easy to talk to.

.................Buckshot

[PatMarlin]

Very nice tools Rick.

I've got to find some tutorial videos or a class somewhere on machining. Problem is the nearest city is 1.75 hours away.

I need to make a steel reducer bushing thats 1 7/16" OD to 1 1/4" ID. x 1 1/4" long. I don't have any boring tools. I know how to cut the OD, but I don't know how I'm going to do the inside?

Maybe I can grind a tool that will fit in my tool post, long enough to get in there after drilling. I think I' ve got about a 7/8" bit.

[Buckshot]

................Get the old South Bend book, "How to Run a Lathe". It's all usefull information and covers most every evolution clearly. Almost nothing about running a manual engine lathe has changed since 1900, so a copy of a 1930's lathe book would definetly be up to date. The only thing not there is messing with carbide insert tooling. The book isn't very expensive at all.

With a piece of HSS and a bar of steel you can make a good boring bar, like below:

http://www.fototime.com/44F25A73466923B/standard.jpg

This is one I made. It's in a boring bar holder but it could be clamped in a regular tool holder. You can get HSS drill blanks which are hardened their full length and grind a cutter. Being as they're round and it's a lot easier to drill a round hole in the boring bar vs a square one, that's the easiest thing to do :-)

Some drill bits are fully hardened, but usually not in the shank. That's left softer so the chuck can get ahold of it. But if you DO have some bits that are fully hardened you could sure cut a piece off the shank and use it for the cutting tool.

If you can pickup a piece of 1" OD steel of most any description it would for sure be rigid enough to bore that depth. Of course your tool holder would have to be able to hold a 1" bar. You could go smaller and just take lighter cuts too.

.................Buckshot