How Do You Form A Taper In A Small Space ?

[DoctorBill]

I just bought an 1895M Nagant Revolver.

http://castboolits.gunloads.com/showthread.php?173797-Reloading-for-the-1895M-Nagant-Revolver-7-62x38R

I am using the LEE Die Set for that revolver, but I'd like to form
a Cone Shaped closed end versus the round crimped end that the
LEE Die makes.

So, I came up with this idea (The LEE 30 Carbine Dies are $39 locally!)
to form a cone shaped closure like the LEE Carbine M31 die would do.

I don't want to spend $42.25 (tax included) for the LEE Die just for this pistol !

I have a 3' section of 7/8ths x 14 TPI steel rod.

http://s19.postimage.org/eh5fi4wir/30_Carbine_Crimper.jpg

At the lower left of the above Photoshop diagram is a picture of the Prvi Partizan Brass
(bottom) from Graf & Sons and then one type of Surplus Russian Cartridges with the Cone
Shaped closure (upper cartridge in the picture).

My question - being a neophyte Lathe user - how do you bore a 4-5°
taper in a small diameter hole (0.296") in steel ?
It would come from making this:

http://s8.postimage.org/7rw7gv71h/Taper_30_Carbine_Crimper.jpg

Yes, I know - you do it carefully...

Tools that small are beyond what I have tried.

Should I make some sort of "D-Bit" ?

DoctorBill

[arjacobson]

I would use a very small boring bar and the compound rest on a lathe

[Mooseman]

Tapered reamer...

[theperfessor]

Second what arjacobson said. Do it in two steps. Drill/ream the .296" & .355" holes from one end and then flip it 180 and cut the taper from the other end, that way the boring bar doesn't need to extend more than 1/2" or so.

[deltaenterprizes]

A tapered D reamer would be a good project and give you desired results with less skill needed than trying to cut an internal taper with the compound. Use the compound to cut the external taper on the drill rod and you will see the difficulty in getting a smooth finish that you will want on the inside of a taper crimp die, but on the external taper you can easily file and polish and measure your work with less effort and more accuracy for a beginner

[DoctorBill]

I was afraid you folks would say that.....

I have tried to grind such a thing like this before -

http://s15.postimage.org/jok7drz4b/Small_Boring_Bit.jpg

Here it is - about twice too large to do what I need....Yikes !

http://s17.postimage.org/4gkx7rl1b/Small_Inside_Bit.jpg

Grinding the above on a 3/16ths HSS bar is freaking difficult - for me at least.
70 year old eyes and not all that steady hands.

Can one do finishing grinding, on a small bit like that, with a Dremel Tool Bit ?

Besides - how do you see what you are doing inside that hole....?

DoctorBill

PS - I suppose I could try BOTH routes - D-Bit and Inside Reaming.
I have enough threaded rod to repeat this several times (assuming a couple of screwups).

[I'll Make Mine]

D-bit tapered reamer -- I wouldn't even attempt to bore an inside taper with a boring bar on my lathe; hard to measure, and impossible to get the surface finish you need for a die (darned near impossible to even tell if it's smooth inside). With a D-bit reamer, if your bit is smooth, and the cut to make the D cutting surface is smooth, you'll get a smooth hole.

To make the D bit, just turn a round rod to your desired profile, then grind a flat face leaving a bit more than half the diameter, a little past the taper. Harden, and polish, before cutting the flat.

[garandsrus]

Dr bill,

The shape of your cutter isnt what was being described. Basically, turn a piece of stock with the outside taper you want and smooth it with a file, sandpaper, etc. then, grind 1/2 of it away. You will need to do some more grinding for relief angles, etc. I have never done one, by the way, so i cant provide detailed instructions.

What you show is pretty much a tapered boring bar.

[deltaenterprizes]

The boring bar does not have enough relief on the side where the point is located, the bottom of the tool will scrape on the part being bored and no cutting will take place.

[DoctorBill]

The one with the pictures is an OLD ONE I made a while back.
I did not mean that I would use THAT one !

The drawing is what I was trying to say that I would have to
make to do what I want using a 3/16ths HSS stock bar.

I did make a tapered crimper for my Martini Henry using a boring bar,
but it is barely usable - it is not smooth like "Down Town".
Well....maybe I am being too critical - it works quite well actually !

The following link and prior posts show what I did - later posts are Off Topic...

http://castboolits.gunloads.com/showthread.php?151167-Attempt-to-make-a-Taper-Crimper-on-my-new-Lathe&p=1719361&viewfull=1#post1719361

But, yes - the D-Bit is probably the best method given the small
aperture that I have to work in. Just have to buy some HSS Drill Rod
of the appropriate diameter....

DoctorBill

[Mooseman]

The problem with a boring bar that small and that long is flex in the bar when trying to cut the taper. This is why I suggested a tapered reamer. Or a chamber reamer !!!

Rich

[Chicken Thief]

When i do tricks like that i reverse the lathe rotation and grind the steel mirrored.
Thus i can see what i'm doing.

But as said you will be in a heap of trouble turning the taper and you can expect a rough surface.
I would opt for a D-bit also, but thats just me.
Easy to measure when you work on it, the hole is "impossible".

[arjacobson]

You are only cutting a taper on the .375 length dimension. I would drill/ream the .355 I.D. Flip it 180(just like the perfessor said) grind a short boring bar with just a bit of radius where the cutting will take place. THIS will get the finish you are after. I think if you make a dbit and try to cut the whole thing at once it is going to chatter like my ex-motherinlaw. You are basically adding 1.180 of un needed length. Use a flashlight and watch the cut carefully. Actually it is a fairly simple operation from the looks of it. If my runout was good I could have probably run the taper in less time it took to write out this description. Even with indicating the part in with a four jaw for perfect runout-setting the taper-doing the cut it- shouldn't take over 1/2 hour including bathroom and coffee breaks..

[DoctorBill]

arjacobson - "if you make a d-bit and try to cut the whole thing at once it is going to chatter like my ex-motherinlaw."

Of course I will pre-drill the whole thing thru with a 19/64ths (7.5mm) drill first, then go in 1.18"
with a 9mm or 23/64ths drill (~ 0.355").

THEN - the D-Bit will have the taper on the outer 0.375" end and be made with a 23/64ths diameter HSS Drill Rod.

http://s19.postimage.org/rrxvpecgz/30_Carbine_Crimper.jpg

The only part the D-Bit has to cut is a very small amount of metal going from the straight to the taper, as
shown in the above diagram - Yellow Lines.

However, I might just try what you suggest with a Bit.
It is just that the hole is not much more than a 1/4" hole !
If I take very small amounts off at a time, maybe I can do it !

I can try both ways....

Also - as shown in the diagram, I was going to lathe away the threads on the
right side. I really don't have to do that - it was for esthetics...

DoctorBill

[waksupi]

I think I'd call Pacific Reamer, and see if they had the proper tool on hand. Bet they do. Rent for cheap.

[DoctorBill]

The entire point is for me to make the tools and Learn !

DoctorBill

[David2011]

DoctorBill,

A friend used to make D-Bit reamers any time he needed to ream internal shapes and they worked great. He rechambered several revolvers with them. You could make a smooth .296" pilot on it and leave the .296" bore area over-length until the taper is completed so there would be something to support the pilot. When done you could cut the extended .296" support area off if you want. It wouldn't hurt anything if you didn't.

David

[DoctorBill]

David2011 - A Capitol Idea ! Yes - the 0.296 'Pilot' is a good idea - wish I had thought of it !

Since it is a straight taper, there is no 'nose' area to consider as if I were reaming a mold for a bullet.

My biggest problem is finding the HSS Drill Rod around this podunk town (Spokane, WA).
Probably have to order it from ENCO or Grizzly and wait for it to be shipped.
It is cold out (23° F) and windy - so I won't be shooting for some time. I'm a wuss.
Warm weather shooter.

Just had an idea ! How about I go to a Pawn Shop and buy a used 23/64ths drill
(if I can find one) and grind the end into the taper and use that for a "D-Bit ?
Hard metal and the right size....

DoctorBill

[I'll Make Mine]

The problem is that you'll be cutting with the flutes on the taper; they aren't made for that, don't have the right angles on them, and will be a major pain to get sharp enough to cut at all. By the time you make a 23/64 twist drill work for this, you could have just made a D-bit.

Alternate sources for drill rod might include Metal Shorts (they have a shop in Seattle, would at least cut shipping time) or your local Fastenal (don't expect good prices, but it's worth calling to see if they have stock rather than waiting for Enco to ship). You might also call a couple local machine shops to see if they have any "drops" -- a piece six inches long is too short to keep when your lathe has a 12" chuck, but it'd be just what you want; you might get it for the gas to drive over and root through the scrap bin.

[elk hunter]

"My biggest problem is finding the HSS Drill Rod around this podunk town "


You don't need HSS for your reamer, a piece of O-1 will do just fine.

[kywoodwrkr]

Tapered reamer...

Think I'd second this.
Tapered reamers have been used and reccommended for chambering reamer bases for years.
I'm currently drawing up some reamers I want to make as a matter of fact.
You'd need something which would act much like a cylindrical grinder to shape the reamer and then
sharpen.
I've got three #8 reamers in transit right now as a matter of fact to test my grinding capability out.
Sizes can be found on internet. Both SAE and metric.
My major concern will be getting proper grinding wheel for our grinder(s).

[deltaenterprizes]

A pilot on the end of the reamer is a good idea.

[Buckshot]

............Dr. Bill, This isn't how you'd do it for a one piece unit such as you show in your drawing, but this is how I'd do a 'work around' for what you're trying to accomplish. I'd simply make an insert type sizer and body. As below:

http://www.fototime.com/57FDCC442C1911E/standard.jpghttp://www.fototime.com/F8A71123107F86F/standard.jpghttp://www.fototime.com/270BFCD63A02CF7/standard.jpg

I make these things for 'Neck Sizing' straight rifle cases. The concept will work for what you want. You already have the dimensions you want, so simply modify the parts shown to meet your particular need's. You WILL need to counterbore the top end to keep your insert from falling down inside the body (Duh). Should be simple to bore the taper you want in the insert. The insert doesn't need to be hardened, but if you want it that way use W-1 or O-1. Harden it now. Re-chuck it (you DID mark it in relation to jaw #1 right?). Use your Dremel and a Cratex disk to polish it, and add a faint radius at the bottom of the insert. Now would be a good time to learn to cut internal threads. If you don't want to, but just get the project done, make the body, make your tapered insert and then a nice slip fitted insert retainer. Run a tapered case up into it until the insert presses against the retainer. Mark the body, then drill a hole through the body and retainer and stick a freaking pin through it.

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

[Doc Highwall]

Buckshot, I made something similar to what you made above except I used a LEE Collet Neck sizing die as the host body. After you take the die apart you have the main body with 7/8-14 threads on the out side and the I.D. is already threaded and has an end cap.

[David2011]

Time to make a grinding adapter for the lathe. Strap your Dremel to the compound and set the taper angle. Grind away in slow passes and you'll have a first class taper. You can even develop the pilot at the same time. Take it to the mill and cut the flat. I've never tried to machine a drill bit but would think it would have to be annealed, machined, hardened and tempered. Still, not hard to do on a small piece of metal. You have my sympathies trying to procure material in a small town. I have the same situation. Still, I prefer smaller town living and access to public land.

David

[I'll Make Mine]

You have my sympathies trying to procure material in a small town.

Heh.

When I was growing up in northern Idaho, Spokane was the big city; I lived in towns under 2000 from age 4 until 10, then moved to Moscow, Idaho, a "city" of 15,000 where I lived until I was 23 (except for seven months in a slightly larger town during an internship).

Then I moved to Seattle; the only thing I missed about small towns was being able to shoot without paying someone for the privilege.

[DoctorBill]

This small WA town is around 300 people and has passed a NO SHOOTING ordinance
and we are out in the middle of a large Farm Area where shooting not prohibited.

Must be that we have a lot of California retirees here....or Liberals who got fed up with
living near each other !

This country is getting 'Buttoned Up' like an old corset !

Even our one 40 year old gun range has been hassled and sued more times than my
cat has hairs on her.

Same story - build and move in next to an Airport or Gun Range and then start complaining
about the noise....anal sphincters.

53% of Americans voted for Obama......we are devolving.

Funny though...how guns sales skyrocket when a gun control candidate wins the election !
Makes no sense - can't just be us collectors deciding to get another firearm.

DoctorBill

[Buckshot]

............If you do live in a small town or an area with no machining supplies, I'd suggest Signing up at Enco and MSC, plus getting on their e-mail list. Right now Enco has a 15% off your order of $149 or more. The will also free shipping codes and sometimes it's on orders pf $99 or more. A few times a year they'll have a free shipping code AND a percent off code. Ordering stock to have on hand is the time to use the free shipping code. I will place items in my shopping cart that I need or would like to have. When I have the means and they have a percent off code I'll pickup as many light things as I have money for. I always use free shipping for heavy items and on the odd times they have both together I try to cover as much as possible.

While I'm 70 miles east of Los Angeles there are several communities around. I'm lucky to have Cal-Mesa Steel 4.5 miles from my driveway, and they carry everything from expanded steel mesh to 'D' series steel. I do occasional machining for my cousin's husband. He does field repair on most any type of construction equipment and was needing a replacement head for a pile driver. He spec'd a 10" OD x 4" thick piece of 4350 steel. I called Cal-Mesa and they had it (well, a band sawed piece I had to mill to thickness) in 3 days. There is also a machine tool dealer about 16 miles away which is handy if you're REALLY desperate for something :-)

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

[smokeywolf]

Great work-around Buckshot. Resourcefulness is one of the most admirable qualities in a machinist.

smokeywolf

[DoctorBill]

I almost have it made now....

Made from threaded rod - I bought a 3 ft section of 7/8" x 14 TPI just for making
reloading Dies and such....from ENCO.

http://s19.postimage.org/8bi9nj06b/Nagant_Cartridge_Crimper.jpg

Just have to make the D-Bit and cut the taper on the inside and I will be done.
Since I don't have the proper size Drill Rod, I might just cut a D-Bit from a hard Steel BOLT.

I'm tired...time for a brew.....standing at a Lathe for a couple of hours is quite tiresome !

DoctorBill

[Buckshot]

"..............standing at a Lathe for a couple of hours is quite tiresome !"

Try it for 2-3 days at a time with people expecting results hanging over your head. I need to find a freaking JOB! :-)

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

[I'll Make Mine]

Just have to make the D-Bit and cut the taper on the inside and I will be done.
Since I don't have the proper size Drill Rod, I might just cut a D-Bit from a hard Steel BOLT.

This is much harder than making the thing from drill rod; the bolt is already hard, but you'll harden the drill rod after you finish cutting. You can grind the bolt, if you have to go this way, a lot more easily than turning it (unless you have carbide tooling and a lathe with enough power to hard turn).

[Wayne Smith]

I probably shouldn't say this after reading this whole thing, but ... I use a 32-20 size die screwed partially in my press to accomplish the same thing.

[DoctorBill]

Well Wayne....I wanted to make mine since I have a new 9x20 inch Lathe and need
something to do besides watching Oprah Winfree or "I Love Lucy" on TV !
I could watch FOX News, but that makes me so depressed, I might use my Nagant
on myself....especially now that that crazy Bugger killed 27 Kids.
Now Obama has fuel to go after our guns - Which Mr. Wonderful wants to do.

Ah well....I can't control ANYTHING, so I might as well tell everyone about my progress
making the D-Bit to cut the taper inside my crimper.

Here is where I am right now.

http://s19.postimage.org/pbtcqud9f/D_Bit_Progress_A.jpg

This fits into my previously made Die perfectly.
http://castboolits.gunloads.com/showthread.php?174301-How-Do-You-Form-A-Taper-In-A-Small-Space&p=1955463&viewfull=1#post1955463

I now have to cut the taper. Should be about 6° angle on the compound.

This should do it - yes ?

http://s19.postimage.org/ooug1bgdf/5_Degree_Angle.jpg

I can almost get there and then finish the taper off with a file.
It doesn't have to be perfect....

Then again......
http://s19.postimage.org/nb2t60h43/Tapered_Pre_D_Bit.jpg

Now to grind it and then harden it.....

DoctorBill

[.22-10-45]

The entire point is for me to make the tools and Learn !

DoctorBill

Hello, DoctorBill. I have made "half" reamers for chambering custom loading dies (.577/.450 M.H.) Using air hardening tool steel. Turn up desired taper, harden..and grind off 1/2 dia. These are more of a scrape cutter..remove as much material from hole as possible..might even rough bore undersized angel..but the finish is excellent.

[DoctorBill]

Done !

http://s19.postimage.org/5g70m5rxf/Tapering_D_Bit.jpg

Went to my machinist friend, Gary, who ground the taper portion on his
tool grinder. Held the rod in a Chuck and ground the taper very precisely.

Gary heated and hardened it in Oil, sharpened it and Walla ! All finished.

He wanted to cut the taper in the die, but I wanted to do that myself.

http://s19.postimage.org/da7m7jzqb/Tapering_Cut_B.jpg
Sacrificed an empty Prvi Bass and the results are in following picture.

http://s19.postimage.org/b6x6zvzxf/Tapered_Brass.jpg

Looks like the smaller hole I drilled could have been smaller still !

Think my taper is OK - but the smaller hole could be even smaller....

However - the cartridge nicely fits into the Nagant when cocked - goes into
the Forcing Cone quite nicely...I may have it ! Test firing will tell.

OK - What's next ? I hate it when I finish a project ! Get bored really fast....
It isn't getting done, it's the process of getting there that is the reward.

DoctorBill

[I'll Make Mine]

Nice photo series, Doc. I'll be doing almost exactly this when I start making push-through sizing dies to get .301 boolits for paper patching -- bore through and ream to .300 (allowing for .001 spring back), counterbore to .310 to accomodate my .309 as-cast boolits, then make up a reamer like yours and cut the taper at around five degrees. Already got the drill rod (for the reamer, and for the base punch to fit the shell holder slot in my press) and the 7/8-14 threaded rod. The threaded rod I have is low carbon, so I'll probably have to case harden the inside after it's polished (and then repolish, since case hardening tends to expand the metal); you may need to harden your taper crimp die, too, if you won't want it to wear out after a couple thousand cases...

[DoctorBill]

"you won't want it to wear out after a couple thousand cases... "

I had to laugh when I read THAT !

Good Lord - I will be lucky to shoot a hundred rounds !

I confess that I get bored if I shoot very much.
Once I get some pattern and realize it ain't gonna get any better,
I go home or switch weapons.

However, I best get a lot of shooting in.
Once Obama gets his UN or European Treaty signed, he will 'give away'
the Second Amendment and have his Squads of BATF Swat Teams and
Dump Trucks go around confiscating our Firearms.

Like happened in Australia. Right ?

DoctorBill

[silverman1]

Also for a one shot job like this, you could use a low carbon steel, and us3e a case hardening compound, like Casenit.
Just heat it cherry red, dip in casenit, re-heat,and quench in water.