K&M neck turning steel cutter – when did yours go dull?

[RonR]

K&M neck turning steel cutter – when did yours go dull?

Hey all, question for anyone using the K&N cutter system for neck turning.

It seems that my standard steel cutter is getting dull. There’s more torsion force on my wrist when turning and more grabbing on the outside of the neck. I can’t tell for sure but the lead edge seems to have a different appearance than the rest of the cutter? Build up?

I’ve got about 800 passes on this cutter. Mostly on trying to make a silk purse out of a sow’s ear…federal brass. I have since learned the error of my ways…

Regards
Ron

EDIT K&M...my bad...mods if you can oblige and change the title...for future reference.

 

[horseman2]

I have a Forster but the carbide cutter went dull . . . my guess is trimming nickel plated brass . . . for me anyways!

 

[308BAR]

I have similar results to what your experiencing. I found it grabbing the neck quite often due to buildup, trying to remove too much at one time or grabbing the necks that had varying thickness on opposing sides. I find making a pass of a thou then setting the cutter to the final thickness helped reduce the grabbing.

I probably had the same amount of brass go through it as you. I did have a extra carbide cutter installed it and still found it grabbed every so often, I'm just lazy and only want to make one pass without readjusting my die. I'm going from 15 thou to12 thou thickness.

I also found that the steel cutter produce a smoother neck than the carbide cutter.

 

[358Rooster]

RonR, you most likely just have a little galling on the cutting edge. High speed steel is pretty hard to dull on brass, especially at such a low cutting speed but with Federal brass being so soft & gummy, it will build and give you the feeling of being dull. If you have a fine honing stone, run the cutter across it to knock that buildup down. Remove the cutter from the tool, place the top face of the cutter flat on the stone and run it back & forth without lifting, so you don't round the actual cutting edge.

I live in Saskatoon as well and if you'd like, I can bring a stone and show you what I mean (my verbal instructions typically suck). A light smear of Rapid Tap (or similar) on the cutter every so often when you're neck turning helps to avoid this galling. For slow speed light cutting operations, it's pretty hard to beat high speed steel cutters.

Rooster

 

[shootnprep]

RonR, you most likely just have a little galling on the cutting edge. High speed steel is pretty hard to dull on brass, especially at such a low cutting speed but with Federal brass being so soft & gummy, it will build and give you the feeling of being dull. If you have a fine honing stone, run the cutter across it to knock that buildup down. Remove the cutter from the tool, place the top face of the cutter flat on the stone and run it back & forth without lifting, so you don't round the actual cutting edge.

I live in Saskatoon as well and if you'd like, I can bring a stone and show you what I mean (my verbal instructions typically suck). A light smear of Rapid Tap (or similar) on the cutter every so often when you're neck turning helps to avoid this galling. For slow speed light cutting operations, it's pretty hard to beat high speed steel cutters.


Rooster

What he said.

 

[RonR]

Hey 308,

I find making a pass of a thou then setting the cutter to the final thickness helped reduce the grabbing. .

That's the method I've incorporated.

I also found that the steel cutter produce a smoother neck than the carbide cutter.

That's what I was looking for. I don't think you are lazy...neck turning gets repetitive fast and I've considered going in one pass myself but being new to the neck turning game and having a failure I've decided to stick by the book so to speak. I'll see if the same process on PRVI and Lapua has any failures.

Much obliged 308 for weighing in.

Regards
Ron

 

[RonR]

RonR, you most likely just have a little galling on the cutting edge. High speed steel is pretty hard to dull on brass, especially at such a low cutting speed but with Federal brass being so soft & gummy, it will build and give you the feeling of being dull. If you have a fine honing stone, run the cutter across it to knock that buildup down. Remove the cutter from the tool, place the top face of the cutter flat on the stone and run it back & forth without lifting, so you don't round the actual cutting edge.

I live in Saskatoon as well and if you'd like, I can bring a stone and show you what I mean (my verbal instructions typically suck). A light smear of Rapid Tap (or similar) on the cutter every so often when you're neck turning helps to avoid this galling. For slow speed light cutting operations, it's pretty hard to beat high speed steel cutters.

Rooster

Thanks for the great response and knowing what I was after.

I took machining in high school and later in tech school to determine feed rates/materials etc. but my a$$ has gotten soft regarding working with metals. I don't have the right stone or have faith in my technique so I'll pm you Rooster for some more information tonight. I'd like to keep using this cutter if possible and not have to order one, in favor of consumables for reloading.

From your response and 308BAR's response it indicates that likely the high speed steel cutter is fine and more than suitable for this operation. I don't think I need the carbide cutter option provided by K&M.

Best Regards
Ron

 

[308BAR]

I'll see if the same process on PRVI and Lapua has any failures.

Much obliged 308 for weighing in.

Regards
Ron

I'm currently neck turning 800+ PRVI cases and have neck turned hundreds of Lapua/Hornady Match brass previously. I can say results would be about the same but less grabby by the Lapua brass because it's more concentric and brass is more uniform, less grabby on Hornady Match because it's not as thick as Lapua or PRVI so not as much brass to turn. If you want to make one pass cuts slow down the RPMs and feed the case in slower into the cutter. Clean often and use a lube (imperial wax) on the outside of the neck and inside pilot.

I find that the carbide cutter still grabs on brass that is not concentric. The carbide cutter benefits from slow RPMs and I'm finding if a carbide cutter is run fast it leaves a rougher surface (tooling marks) then the HSS but a smoother surface can be achieve but not as smooth as HSS in comparison side by side. You can definitely run the HSS at a slightly higher RPM and still produce a smooth surface. However I'm finding the weakest link in the neck turning process is the case holder with the lee shell holder bloody thing doesn't hold the case tight unless tighten with a wrench.

 

[358Rooster]

A few points:

• Whether using carbide or HSS, neck turning should be a low speed operation. If you're using a drill, that's fine, but don't try to use it at 2500 RPM & expect good results
• Carbide cutters were developed for production. HSS is much tougher (not as brittle as carbide) and is still king for finish at low speeds. Carbide requires high speed / slow feed for fine finishes. And be careful to not reverse the material against a carbide cutter - this can chip the cutting edge in the carbide and give you worse finishes.
• Brass can gall on carbide too
• I've plowed though a lot of thick necks b/c I'm too damned lazy to reset the cutting depth. When you do that, there is some tool deflection or material movement. I let the brass cool down (friction from the fit on the mandrel) and take another "skim" cut w/o adjusting the cutter and it gives a good result
• I have a feeling a lot of people don't expand necks prior to turning. This can play a big role in how much you need to muscle through this operation. If your holder won't grip tight enough, maybe the problem isn't the holder.
• Imperial wax won't help you much on the outside of the neck but it sure helps on the mandrel for the inside of the neck

Ron, when we get together, I'll show you how to tune up that cutting edge with a stone too. I've seen a lot of cutters for various case prep tools supplied with a crappy edge - like they baby-proofed it or something!

Rooster

 

[RonR]

I can say results would be about the same but less grabby by the Lapua brass because it's more concentric and brass is more uniform,

However I'm finding the weakest link in the neck turning process is the case holder with the lee shell holder bloody thing doesn't hold the case tight unless tighten with a wrench

That's been my exact experience but with Federal brass. Lapua more consistent than PRVI, PRVI much more consistent than Federal.

Wrench usage too but I just incorporated wrench use every time and developed some efficiencies into loading/unloading cases into the holder. It was slower but worked every time and prevented the litany of profanity after the X'th time the cartridge spun out. This however let me concentrate on other subtleties and that's how I discovered the cutter not performing as well. However the K&M holder system is bar far an improvement over the similar Lee system. Easier on the fingers and faster for situations like when I used to polish cases with SS wool after chamfer/de-burring. I have nothing bad to say about Lee products, just the K&N holder system is better IMHO base on my short reloading career.

My RPM is slow, can't specify exactly how much but the filings are curling off the case necks, and if I remember correctly from my limited experience with learning machining, that's about the right feed rate and RPM...but what do I know?

I am more confident that HSS cutter for a material is the right call for this application and that in itself is good to know.

Thanks for your time and responses 308. Have fun turing those 800 cases

Regards
Ron

 

[RonR]

A few points:

• Whether using carbide or HSS, neck turning should be a low speed operation. If you're using a drill, that's fine, but don't try to use it at 2500 RPM & expect good results
• Carbide cutters were developed for production. HSS is much tougher (not as brittle as carbide) and is still king for finish at low speeds. Carbide requires high speed / slow feed for fine finishes. And be careful to not reverse the material against a carbide cutter - this can chip the cutting edge in the carbide and give you worse finishes.
• Brass can gall on carbide too
• I've plowed though a lot of thick necks b/c I'm too damned lazy to reset the cutting depth. When you do that, there is some tool deflection or material movement. I let the brass cool down (friction from the fit on the mandrel) and take another "skim" cut w/o adjusting the cutter and it gives a good result
• I have a feeling a lot of people don't expand necks prior to turning. This can play a big role in how much you need to muscle through this operation. If your holder won't grip tight enough, maybe the problem isn't the holder.
• Imperial wax won't help you much on the outside of the neck but it sure helps on the mandrel for the inside of the neck

Ron, when we get together, I'll show you how to tune up that cutting edge with a stone too. I've seen a lot of cutters for various case prep tools supplied with a crappy edge - like they baby-proofed it or something!

Rooster

Excellent summary and explanation. Cutter material differences explained to match application.

I didn't want the ID of the neck to be an opportunity for error so I use the K&M neck expander die and so far with Imperial lube seems to be working as intended. (Some others have used the Lee collet die to set ID so that it would work but for me it was one more variable that could be eliminated.)

We'll be in touch and thanks for your responses Rooster!

Regards
Ron