How does one obtain consistent results when neck turning

[B_Thomas]

View attachment 1010477 Neck expansion is a whole other subject that affects not only neck turning but also, and more importantly, neck tension, as in bullet release.

I had been struggling to find a solution to all these neck expansion problems for about a year. I eventually focus on the Hornady bullet puller collet, because that's what I had. I started using pin gages to expand the necks to match the turner mandrel.

However, the bullet puller did not hold the pin gages as co-axially straight as I wanted, so I approached Kenny Porter, who is master machinist for all kinds of things including parts for pacemakers (can you think of anything more critical?). I told him I wanted him to make a die for me that would hold a pin gage, actually a range of pin gages ie .305, .306, .307, .308 and .309. Once I showed him what I had in mind he made a leap to a collet that is ideally suited for what I wanted. The collet holds the cutting bit for a CNC machine. It has real holding power.

Here's what his brain and hands produced:

View attachment 1010467


View attachment 1010468

View attachment 1010469


Now all I have to do is measure the cutter mandrel and I use a Vermont pin gage ($4 on Amazon) to expand the neck to whatever I think its appropriate.

Joe

Are these available for purchase? Very Nice setup!!!

 

[Joe R]

A nice setup. It's good to see what a master machinist can do. I may have a use for some of the pin gauges. Didn't know they were that cheap and available. I only turn .308's and the K&M expander works ok for that. The necks are snug enough not to fall off the mandrel but loose enough to easily be turned with my fingers. I use it sometimes as a final sizing of the neck and it produces about .001" interference fit. I run my 208 grain load hot so just little tension works without increasing pressure. I have checked and the tool doesn't move the neck out of alignment. I get the same runout either way. The mandrels are available in custom sizes by special order. The screw bottoms out in the case and prevents ramming the neck into the holder.

You know, that die is exactly what drove me to create the one that Kenny Porter made.

I bought that die, including the little window thingy, I still have it. The mandrel that came with it was .002 off from what I was told. I called back and told Roger and he basically told me that if I wanted something that exact I would have to order a custom mandrel for $27. So I did, and when I got it once again the mandrel was off by .0005. I called Roger back and then he proceeded to try to tell me that my micrometer wasn't any good. When I told him that I use a Mitutoyo that measures to .00001, he told me that I must have dropped mine and it was malfunctioning. Then I explained to him that I also use class X Deltronic pin gages to verify it my micrometer he hung up on me.

It was obvious to me that K&M is pretending to be a precision shop when all they do is scam users. There are many people here misrepresenting themselves when they are nothing more than a shill. Here is the definition:
shill
(shĭl) Slang
n.
1. One who poses as a satisfied customer or an enthusiastic gambler to dupe bystanders into participating in a swindle.
2. One who publicly promotes another's cause, especially in an extravagant or misleading way.

 

[T-shooter]

You know, that die is exactly what drove me to create the one that Kenny Porter made.

I bought that die, including the little window thingy, I still have it. The mandrel that came with it was .002 off from what I was told. I called back and told Roger and he basically told me that if I wanted something that exact I would have to order a custom mandrel for $27. So I did, and when I got it once again the mandrel was off by .0005. I called Roger back and then he proceeded to try to tell me that my micrometer wasn't any good. When I told him that I use a Mitutoyo that measures to .00001, he told me that I must have dropped mine and it was malfunctioning. Then I explained to him that I also use class X Deltronic pin gages to verify it my micrometer he hung up on me.

It was obvious to me that K&M is pretending to be a precision shop when all they do is scam users. T-shooter, with only 76 posts, I suspect that you are noting more than a shill. Here is the definition for you:
shill
(shĭl) Slang
n.
1. One who poses as a satisfied customer or an enthusiastic gambler to dupe bystanders into participating in a swindle.
2. One who publicly promotes another's cause, especially in an extravagant or misleading way.

Could be, I only purchased once and had no issues. I don't promote anything, just tell from my experience what works for me. I could care less who uses what. Besides, I just joined this forum about 50 days ago. You should learn something about the individual before resorting to name calling.

 

[Joe R]

Are these available for purchase? Very Nice setup!!!

Thomas,
You can contact Kenny Porter at (979) 798-9422 or kennethp@portersprecisionproducts.com hence the P3 logo on the die.

My only affiliation with Kenny is as a satisfied customer. He also happens to be a superb sling shooter. He happens to be the current NRA High Power 1,000 yard Metallic Sights record holder with a 200-19X. And to top it all off, he is an nice guy and as honest as day is long. My kind of guy.

Kindest regards,

Joe

 

[LHSmith]

There is nothing wrong with K&M's neck turning system. Been using them for a lot of years. I have 5 sets,each one dedicated to a competition cartridge. The lack of a carbide mandrel, course adjustment range and lack of providing the all-important matching expander ....the Hornady tool would be a deal breaker for me. Not to mention that K&M inventories a large range of calibers and they will cater to special requirements.

 

[Brians356]

I have the Hornady L&L lathe-style, same as "Joe R". In fact his original video (and helpful e-mail exchange) inspired me to try the L&L myself, and it works great since I can live with neck wall variation of <= .0003" without using a custom expanding mandrel like Joe has. (A closer fit on the Hornady turning mandrel will probably yield smaller variance; I'm just using a Sinclair expander which is close enough for my requirements.)


-

 

[Brians356]

However, the bullet puller did not hold the pin gages as co-axially straight as I wanted, so I approached Kenny Porter, who is master machinist for all kinds of things including parts for pacemakers (can you think of anything more critical?). I told him I wanted him to make a die for me that would hold a pin gage, actually a range of pin gages ie .305, .306, .307, .308 and .309. Once I showed him what I had in mind he made a leap to a collet that is ideally suited for what I wanted. The collet holds the cutting bit for a CNC machine. It has real holding power.

Joe,

Did Porter make the entire die, or just the collet?

So the single die could be used for several calibers with just different spec collet inserts, yes?
-

 

[Joe R]

Joe,

Did Porter make the entire die, or just the collet?

So the single die could be used for several calibers with just different spec collet inserts, yes?
-

Hi Brian,
The collet is actually an Accupro collet. He buys them a bunch at the time to save a on shipping etc... The mandrels are Vermont Gage pin gages that he also buys. He makes the die and it is very nice die with a taper to compliment the collet. He has improved substantially over my prototype. I basically need a collet for each caliber. I believe he sells the die body a collet and 1 mandrel for approximately $120. See picture

Joe

 

[BoydAllen]

I have a lot of neck turning equipment from different makers. Back before I had so much to choose from I had a system that worked. Like a lot of people who were running .262 neck 6mmPPCs, I turned my necks to .0086 thickness. My process involved the use of two turners. The rough cut, to within approx. .001 was an old Sinclair turner, the simplest and cheapest that they made. Growing tired of heating and mandrel brassing issues I had sanded the mandrel down a bit to make a more relaxed fit in expanded necks. The result was virtually no heat, or brassing, but getting the best results was extremely technique sensitive. Some time later, as a result of my product writing for Shooters News, I was given a K&M turning setup to test, back when Ken Markle owned the company. It came with a carbide mandrel, that I soon determined tended to do things to the insides of case necks that I did not like, because of the built in doughnut cutter. A little work on the cutter's edges and corners with a cheap coarse diamond lap fixed that problem. Anyway, the K&M setup did a fine job, except that It seemed that if I did the necks with a single turning that the fit of the neck on the turning mandrel was tighter than I liked. About that time I decided to set up my old Sinclair tool to make the rough cut. With its reduced turning mandrel diameter, it made no heat, and as I mentioned earlier, their were not brassing issues. Using it for a rough cut gave one additional advantage. The fit of the brass on the K&M mandrel was improved, loosened up a bit, but not really loose, result much less heat, while maintaining excellent neck uniformity. After trying a number of neck turning lubes, all of which worked to one degree or another, I settled on....wait for it ...drum roll,,,a dark red thin oil that Kinneman sold me a small plastic squeeze bottle of for what seemed like a lot of money twenty years ago. I think that it cost five dollars. If someone has figured out what it is, I would like to know, even though I am not going to run out...just curious. Anyway, the other tricks, for the finish cut, are slow speed, and only making one trip across the neck, too fast to cut cleanly on the way to the shoulder, and very slow on the way back, (cutting both ways). I do not like to keep either the driven case or the tool from wobbling, none of this vise stuff. The last tip came from my brassing problems with the non carbide mandrel Sinclair turner. I check every case neck for thickness, right after it is finish turned and power spun in a wad of 0000 steel wool to refine the finish to something more like it will be after a couple of firings. Others have said that necks shrink a little if you wait too long to turn after expanding. That is correct.They do. If you don't get them all turned the day that you expand them, plan on expanding them again before you turn them, also, expander mandrel dwell time in necks has an effect, more time, more expansion.
To reinforce the two most important things, keep the RPMs slow, and use a carbide turning mandrel.

 

[Mulligan]

I have a lot of neck turning equipment from different makers. Back before I had so much to choose from I had a system that worked. Like a lot of people who were running .262 neck 6mmPPCs, I turned my necks to .0086 thickness. My process involved the use of two turners. The rough cut, to within approx. .001 was an old Sinclair turner, the simplest and cheapest that they made. Growing tired of heating and mandrel brassing issues I had sanded the mandrel down a bit to make a more relaxed fit in expanded necks. The result was virtually no heat, or brassing, but getting the best results was extremely technique sensitive. Some time later, as a result of my product writing for Shooters News, I was given a K&M turning setup to test, back when Ken Markle owned the company. It came with a carbide mandrel, that I soon determined tended to do things to the insides of case necks that I did not like, because of the built in doughnut cutter. A little work on the cutter's edges and corners with a cheap coarse diamond lap fixed that problem. Anyway, the K&M setup did a fine job, except that It seemed that if I did the necks with a single turning that the fit of the neck on the turning mandrel was tighter than I liked. About that time I decided to set up my old Sinclair tool to make the rough cut. With its reduced turning mandrel diameter, it made no heat, and as I mentioned earlier, their were not brassing issues. Using it for a rough cut gave one additional advantage. The fit of the brass on the K&M mandrel was improved, loosened up a bit, but not really loose, result much less heat, while maintaining excellent neck uniformity. After trying a number of neck turning lubes, all of which worked to one degree or another, I settled on....wait for it ...drum roll,,,a dark red thin oil that Kinneman sold me a small plastic squeeze bottle of for what seemed like a lot of money twenty years ago. I think that it cost five dollars. If someone has figured out what it is, I would like to know, even though I am not going to run out...just curious. Anyway, the other tricks, for the finish cut, are slow speed, and only making one trip across the neck, too fast to cut cleanly on the way to the shoulder, and very slow on the way back, (cutting both ways). I do not like to keep either the driven case or the tool from wobbling, none of this vise stuff. The last tip came from my brassing problems with the non carbide mandrel Sinclair turner. I check every case neck for thickness, right after it is finish turned and power spun in a wad of 0000 steel wool to refine the finish to something more like it will be after a couple of firings. Others have said that necks shrink a little if you wait too long to turn after expanding. That is correct.They do. If you don't get them all turned the day that you expand them, plan on expanding them again before you turn them, also, expander mandrel dwell time in necks has an effect, more time, more expansion.
To reinforce the two most important things, keep the RPMs slow, and use a carbide turning mandrel.

Good stuff Boyd, thanks for weighing in on this.
CW

 

[T-shooter]

I have a lot of neck turning equipment from different makers. Back before I had so much to choose from I had a system that worked. Like a lot of people who were running .262 neck 6mmPPCs, I turned my necks to .0086 thickness. My process involved the use of two turners. The rough cut, to within approx. .001 was an old Sinclair turner, the simplest and cheapest that they made. Growing tired of heating and mandrel brassing issues I had sanded the mandrel down a bit to make a more relaxed fit in expanded necks. The result was virtually no heat, or brassing, but getting the best results was extremely technique sensitive. Some time later, as a result of my product writing for Shooters News, I was given a K&M turning setup to test, back when Ken Markle owned the company. It came with a carbide mandrel, that I soon determined tended to do things to the insides of case necks that I did not like, because of the built in doughnut cutter. A little work on the cutter's edges and corners with a cheap coarse diamond lap fixed that problem. Anyway, the K&M setup did a fine job, except that It seemed that if I did the necks with a single turning that the fit of the neck on the turning mandrel was tighter than I liked. About that time I decided to set up my old Sinclair tool to make the rough cut. With its reduced turning mandrel diameter, it made no heat, and as I mentioned earlier, their were not brassing issues. Using it for a rough cut gave one additional advantage. The fit of the brass on the K&M mandrel was improved, loosened up a bit, but not really loose, result much less heat, while maintaining excellent neck uniformity. After trying a number of neck turning lubes, all of which worked to one degree or another, I settled on....wait for it ...drum roll,,,a dark red thin oil that Kinneman sold me a small plastic squeeze bottle of for what seemed like a lot of money twenty years ago. I think that it cost five dollars. If someone has figured out what it is, I would like to know, even though I am not going to run out...just curious. Anyway, the other tricks, for the finish cut, are slow speed, and only making one trip across the neck, too fast to cut cleanly on the way to the shoulder, and very slow on the way back, (cutting both ways). I do not like to keep either the driven case or the tool from wobbling, none of this vise stuff. The last tip came from my brassing problems with the non carbide mandrel Sinclair turner. I check every case neck for thickness, right after it is finish turned and power spun in a wad of 0000 steel wool to refine the finish to something more like it will be after a couple of firings. Others have said that necks shrink a little if you wait too long to turn after expanding. That is correct.They do. If you don't get them all turned the day that you expand them, plan on expanding them again before you turn them, also, expander mandrel dwell time in necks has an effect, more time, more expansion.
To reinforce the two most important things, keep the RPMs slow, and use a carbide turning mandrel.

I've always used a touch of Hornady Unique case lube on a Q-tip in the necks before expanding and never did see a brassing problem while turning. I have a non-carbide mandrel. It could be caused by too much heat and too little lubrication. I did notice like you said that leaving the expander longer seems to open a bit more. I've done that if I had one that felt more tight than the others. I've only turned .308's and usually try for .0125" wall thickness and sometimes an additional .0005" cut if they need it. Sometimes even that doesn't clean them up all the way around but at least the heavier side is getting thinned and the neck tension should be more even. I've had some Winchester cases that weren't touched by that setting. And it seems like hit or miss luck with Lapua. Some lots will cut nearly 100% of the circumference and others mostly just on one side. The same with Hornady Match cases.

 

[Brians356]

I have a lot of neck turning equipment from different makers. Back before I had so much to choose from I had a system that worked. Like a lot of people who were running .262 neck 6mmPPCs, I turned my necks to .0086 thickness. My process involved the use of two turners. The rough cut, to within approx. .001 was an old Sinclair turner, the simplest and cheapest that they made. Growing tired of heating and mandrel brassing issues I had sanded the mandrel down a bit to make a more relaxed fit in expanded necks. The result was virtually no heat, or brassing, but getting the best results was extremely technique sensitive. Some time later, as a result of my product writing for Shooters News, I was given a K&M turning setup to test, back when Ken Markle owned the company. It came with a carbide mandrel, that I soon determined tended to do things to the insides of case necks that I did not like, because of the built in doughnut cutter. A little work on the cutter's edges and corners with a cheap coarse diamond lap fixed that problem. Anyway, the K&M setup did a fine job, except that It seemed that if I did the necks with a single turning that the fit of the neck on the turning mandrel was tighter than I liked. About that time I decided to set up my old Sinclair tool to make the rough cut. With its reduced turning mandrel diameter, it made no heat, and as I mentioned earlier, their were not brassing issues. Using it for a rough cut gave one additional advantage. The fit of the brass on the K&M mandrel was improved, loosened up a bit, but not really loose, result much less heat, while maintaining excellent neck uniformity. After trying a number of neck turning lubes, all of which worked to one degree or another, I settled on....wait for it ...drum roll,,,a dark red thin oil that Kinneman sold me a small plastic squeeze bottle of for what seemed like a lot of money twenty years ago. I think that it cost five dollars. If someone has figured out what it is, I would like to know, even though I am not going to run out...just curious. Anyway, the other tricks, for the finish cut, are slow speed, and only making one trip across the neck, too fast to cut cleanly on the way to the shoulder, and very slow on the way back, (cutting both ways). I do not like to keep either the driven case or the tool from wobbling, none of this vise stuff. The last tip came from my brassing problems with the non carbide mandrel Sinclair turner. I check every case neck for thickness, right after it is finish turned and power spun in a wad of 0000 steel wool to refine the finish to something more like it will be after a couple of firings. Others have said that necks shrink a little if you wait too long to turn after expanding. That is correct.They do. If you don't get them all turned the day that you expand them, plan on expanding them again before you turn them, also, expander mandrel dwell time in necks has an effect, more time, more expansion.
To reinforce the two most important things, keep the RPMs slow, and use a carbide turning mandrel.

Boyd,

What neck wall thickness variance do you achieve with your approach?
-

 

[BoydAllen]

Back when I started turning, the standard was +- .0001" Recently I cleaned up a set of cases that still have some life left in them, removing all of the fouling from the inside and outside of the necks (the former compensated for by the application of a wax based material after measuring, to make the coefficient of friction similar to a fouled neck, and to prevent welding) Those cases were twice as good as the old standard. or better, measured in the middle of the necks.

 

[Brians356]

Back when I started turning, the standard was +- .0001" Recently I cleaned up a set of cases that still have some life left in them, removing all of the fouling from the inside and outside of the necks (the former compensated for by the application of a wax based material after measuring, to make the coefficient of friction similar to a fouled neck, and to prevent welding) Those cases were twice as good as the old standard. or better, measured in the middle of the necks.

Wow. Incredible. That's beyond my ability to measure positively.
-

 

[BoydAllen]

It is not all that hard, but it does require practice with a neck mic. I did not say that that is what is required. It probably isn't, but when you can read to .0001 directly using the vernier, and can see when you are half way between, the real trick is being consistent, and there is nothing like practice to make you better at that. I mentioned that I squeeze a wad of 0000 steel wool around newly turned necks, while the case is still in the power drive adapter, and under power, spinning it for a couple of seconds to improve the surface finish. I started doing this after I noticed that there was a difference between fired necks and newly turned, which were very slightly (perhaps .0001) thicker because of very fine ridging from the cutter. Another trick that I should have mentioned is a a headband binocular magnifier. Mine is an inexpensive one, that a friend gave me years ago when he replaced it with a better one. It is one of the handiest tools that I have. With my moderate nearsightedness, and my regular glasses off, the minimum focus distance from the front of the lenses is about 7". You don't want them much stronger because working closer would result in problems working with both eyes. You would have to close one, and at that point, what would be the point of a binocular magnifier?

 

[Brians356]

It is not all that hard, but it does require practice with a neck mic. I did not say that that is what is required. It probably isn't, but when you can read to .0001 directly using the vernier, and can see when you are half way between, the real trick is being consistent, and there is nothing like practice to make you better at that. I mentioned that I squeeze a wad of 0000 steel wool around newly turned necks, while the case is still in the power drive adapter, and under power, spinning it for a couple of seconds to improve the surface finish. I started doing this after I noticed that there was a difference between fired necks and newly turned, which were very slightly (perhaps .0001) thicker because of very fine ridging from the cutter. Another trick that I should have mentioned is a a headband binocular magnifier. Mine is an inexpensive one, that a friend gave me years ago when he replaced it with a better one. It is one of the handiest tools that I have. With my moderate nearsightedness, and my regular glasses off, the minimum focus distance from the front of the lenses is about 7". You don't want them much stronger because working closer would result in problems working with both eyes. You would have to close one, and at that point, what would be the point of a binocular magnifier?

Good stuff. I'm fair with the vernier mic. I feel it's the somewhat irregular surface inside the neck, against the tiny contact patch of the ball anvil, which is the source of the measurement inconsistency.

I also rely heavily on my binocular OptiVisor - couldn't live without it! A couple of other avocations here are model building and guitar repair, that latter a source of pocket money, and details matter to paying customers.
-

 

[alintx]

Any one here turn by hand?

Yep. Still use an old marquart i bought from Howard deitz about 35 yrs ago. Slow, but absolutely perfect cuts with the two pass method. It works for me!

 

[dcali]

The biggest killer of consistency in my experience has been a poor match of expanding mandrel to turning mandrel. If the expander is even a little too big, it wrecks everything.

One thing I've rarely seen discussed is just not expanding. I can always seem get away with taking new brass out of the box, and turning straight away. It's a little tighter than it ought to be, but if you use a carbide mandrel, it works without issue. This is assuming a factory brass caliber, and not necking up/down, etc. It might not always work, but I've not yet run across a batch that couldn't be done this way.

 

[Bamban]

I use a 21st Century turning tool, one for every caliber i shoot, the turning mandrel has been Melonited. It is not carbide, but dang slick and hard, my Nicholson file will not even bite into it.

I use my 9x20 mini lathe that the tailstock has been trued straight with the headstock. The floating shell holder is held in the TS by an E32 collect MT2 shank. The TS being modified with a hand wheel, driving the case into the spinning neck turner is just turn or so from the wheel.

 

[perry42]

I have always found that turning a slower speed gave better results but have stayed away from using steel wool to essentially polish the neck. Reading posts let me discover how using Nylon scrubber pads after turning gives me a polished surface that I'm more than pleased with. Thanks to all that that pass on easy solutions to potential/apparent reloading problems.

perry42