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Lee collet dies, why is mandrel made to exact bullet diameter, kinda loose...

What kind of micrometer are you using and when was it last checked using standards ?

Just added signal noice or static for you truly good shooters but I like reminding us all of this regarding some relevant machining accuracy. I do work at the State of CA DOT headquarters Materials Testing Laboratory . . .. . so I took my $19 Harbor freight micrometer over to the tech boys and . . .. .. dead on and matched their Starret and Mitutuyo calibrated tools in every aspect of accuracy but was "rough" to operate.
 
Just added signal noice or static for you truly good shooters but I like reminding us all of this regarding some relevant machining accuracy. I do work at the State of CA DOT headquarters Materials Testing Laboratory . . .. . so I took my $19 Harbor freight micrometer over to the tech boys and . . .. .. dead on and matched their Starret and Mitutuyo calibrated tools in every aspect of accuracy but was "rough" to operate.
Why would you do that if you have the knowledge and experience yourself ? I've used the cheap ones and have found that they may be correct one minute and off the next .
Just saying !
 
Mac, I don't have the experience and that's one reason I try to find the best advice I can get, and to try and get some answers for myself so I don't rely completely on what others tell me. This is easily the best source of information in our disciple and sport on the web. The Starret gauge, one single one, cost more than my rifle from the Barrel at Big 5. Have to start somewhere !!
 
Mac, I don't have the experience and that's one reason I try to find the best advice I can get, and to try and get some answers for myself so I don't rely completely on what others tell me. This is easily the best source of information in our disciple and sport on the web. The Starret gauge, one single one, cost more than my rifle from the Barrel at Big 5. Have to start somewhere !!
Sorry I didn't mean for it to read that way , just that they can be difficult working daily . A Chinese or good used micrometer can be had for less than $50 a Chinese with stds is about $25 . We all started little at a time . It's better to use a micrometer , even a cheap one , so you don't get chasing your tail when the digital cal goes haywire.
If you decide on going the Mike route I can suggest a few . I don't trust battery operated inexpensive measuring tools , I have learned an expensive and embarrassing lesson .
Pm me if interested in the decent company and mics
 
With all respect to both you and Lee-

1. Lee instructions on set up plain old stinks.

2. For you- try the below. It was written by a poster named Valentine and reposted several times by member Kielly. I tried it and followed the instructions. It works.

The Lee is good IMO. I use it exclusively for calibers Lee makes the dies for, but it's only as good as you set it up. Take a look at the Lee collet die bible for me:

Using The Lee Collet Die.
I started using Lee collet dies when they first came on the market and have found that they are very good for the purposes for which they were designed .
I have found that there is a lack of understanding of how to use the die properly and as a result people fail to see the advantages that the die can deliver over standard neck sizing dies.
This is not the fault of the product , it is just a lack of understanding of how the die works and what it will feel like when you operate the press correctly.
Standard dies use a neck expanding ball on the decapping rod and size by extruding the neck through a hole and then drag the expander ball back through the inside neck.
The collet die achieves neck sizing by using a split collet to squeeze the outside of the case neck onto a central mandrel which has the decapping pin in it’s base .
One advantage is that there is no stretching or drawing action on the brass.
The inside neck diameter is controlled by the diameter of the mandrel and to some extent by the amount of adjustment of the die and the pressure applied to the press .
This results in less misalignment than can occur in standard dies because of any uneven neck wall thickness in the cases .
Cases will last longer in the neck area and require less trimming. If cases have very uneven neck wall thickness then this can cause problems for the collet die they definitely work smoother and more accurately with neck turned cases but it is not essential.
When you first receive the die unscrew the top cap and pull it apart check that everything is there also that the splits in the collet have nothing stuck in them then inspect the tapered surface on the top end of the collet and the internal taper of the insert to make sure there are no metal burs that might cause it to jamb.
Next get some good quality high pressure grease and put a smear onto the tapered surface of the collet .
Put it back together and screw it into the press just a few threads for now . The best type of press for this die is a press of moderate compound leverage that travels over centre .
Over centre means that when the ram reaches its full travel up it will stop and come back down a tiny amount even though the movement on the handle is continued through to the stop .
eg. is an RCBS Rockchucker.
This arrangement gives the best feel for a collet die sizing operation.
Place the shell holder in the ram and bring the ram up to full height then screw the die down until the collet skirt just touches on the shell holder , then lower the ram .
Take a case to be sized that has a clean neck inside and out and the mouth chamfered and place it in the shell holder.
Raise the ram gently feeling for resistance if none , lower the ram.
Screw the die down a bit at a time .
If you get lock up ( ram stops before going over centre) before the correct position is found then back it off and make sure the collet is loose and not jammed up in the die before continuing then raise the ram feeling for any resistance , keep repeating this until you feel the press handle resist against the case neck just at the top of the stroke as the press goes over centre and the handle kinder locks in place .
This takes much less force than a standard die and most people don’t believe any sizing has taken place .
Take the case out and try a projectile of the correct caliber to see how much sizing has taken place.
If it’s still too loose adjust the die down one eighth of a turn lock it finger tight only and try again .
Once the die is near the correct sizing position it takes very little movement of the die to achieve changes in neck seating tension .
This is where most people come undone , they move the die up and down too much and it either locks up or doesn’t size at all .
It will still size a case locking it up but you have no control over how much pressure is applied and some people lean on the press handle to the point of damaging the die. A press like the RCBS Rockchucker , that goes over centre each time gives you a definite stopping point for the ram and the pressure that you apply .
There is a small sweet spot for correct collet die adjustment and you must find it , once found , how sweet it is ! Advantages : With a press that travels over centre it is possible to adjust the neck seating tension within a very limited zone. No lubricant is normally required on the case necks during sizing .

If you still cant get enough neck tension to hold the bullet properly for a particular purpose then you will have to polish down the mandrel.
Be careful poilishing the mandrel down and only do it a bit at a time as a few thou can be removed pretty quickly if you overdo it.
You can't get extra neck tension by just applying more force. The amount of adjustment around the sweet spot is very limited and almost not noticable without carrying out tests.
For example , to go from a .001 neck tension to a .002 or .003 neck tension you would be talking about polishing down the mandrel.

There are some other advantages but I will leave you the pleasure of discovering them .
One disadvantage that I have found with the collet die is that it needs good vertical alignment of the case as it enters the die or case damage may result so go slowly.
Also some cases with a very thick internal base can cause problems with the mandrel coming in contact with the internal base before the sizing stroke is finished.
If pressure is continued the mandrel can push up against the top cap and cause damage . If you are getting lock up and cant get the right sizing sweet spot, then check that the mandrel is not too long for the case you can place a washer over the case and onto the shell holder and size down on that.
It will reduce the length of neck sized and give the mandrel more clearance. If it sizes Ok after adding the washer then the mandrel could be hitting the base.
This is not a usually problem once you learn how to use them .
The harder the brass is the more spring back it will have so very hard brass will exhibit less sizing than soft brass because it will spring away from the mandrel more. If this is happening to excess then use new cases or anneal the necks.
Freshly annealed brass can drag on the mandrel a bit in certain cases because it will spring back less and result in a tighter size diameter.
I have experienced it. I always use some dry lube on the inside and outside if I get any draging effect . Normally you dont need lube.
I make up a special batch 1/3 Fine Moly powder. 1/3 Pure graphite. 1/3 Aluminiumised lock graphite. Rub your fingers around the neck and It sticks very well to the necks by just dipping it in and out and tapping it to clear the inside neck . After a few cases it coats up the mandrel .
Other dry lubricants would work also.
Use the same process for normal neck sizing also.

I noticed a definite improvement in the accuracy of my 22-250Rem. as soon as I started using a Lee collet die instead of my original standard neck die.
Readers are encouraged to utilise the benefits of responsible reloading at all times. Although the author has taken care in the writing of these articles no responsibility can be taken by the author or publisher as a result of the use of this information.
John Valentine. © 21/01/2002.


This might actually solve your problem right at the start. I hope this helps, because the only other explanation I can think of is that Lee mismatched the mandrel to the housing of the die shipped.
 
I found the first thing to check is see what you actually need to get the neck size down to. It is base on a combination of the neck wall thickness and the caliber. Second, DO NOT cam over the press when using the collet die. Screws up the petals in the die "Don't ask me how I know! Press the brass into the, die, then take it down a bit, then turn the case, repeating the press-rotate a couple times and you get to your neck size desired. So you decide you neck tension, then remember there is about .001 spring back. Works like a charm for me. I can get a consistent neck size, neck tension and bullet release. Good luck.
 
I received some information from Lee this morning. They stated that their mandrels are 0.002” smaller than the bullet diameter (+/- 0.0005”). That would say for my 6.5 Creedmoor, the standard mandrel diameter would be 0.264-0.002 or 0.262. I’m not at home right now, but I believe I measured exactly 0.264”...,..maybe I got a bad one?

Can anyone out there verify their standard LCD mandrel is 0.002” less than the bullet diameter. It makes sense that it would be.

Don
I just measured the standard one in my 6BR die and it measured .241" with my Starrett. I also have a .240" mandrel and that's what I seem to get the best accuracy with. My process is to size once, turn 180 degrees and hit it again. Works for me, but I'm no expert. If I turned necks, I'd prolly just use a bushing die.
 
Yes but......the Valentine method of setting an LCD better contributes to maintaining case datum length by applying more force onto the case shoulder so to not have issue with case length and bolt closing.

In the smaller calibers like 223 this is not such an issue but with the larger ones it is.
For my small calibers I use the LEE setup method while the bigger ones require the Valentine setup to keep their shoulders nudged back.
Tricky as the Valentine method can be to setup correctly, the effort is worth it IMHO.
 
Homerange - I can't see any way a Lee collet die has anything to do with the shoulder. The amount of case neck that gets sized is dependent upon how the collet portion of the die is machined. How deeply the die is screwed into the press, or how much the press arm is leaned on won't change that.

I have used LCD extensively and think I have a pretty good understanding of them, although reading this thread has increased my understanding. Early in this thread when the Valentine method was referenced, I thought since I knew how to use an LCD what could this method offer, but now I think it is genius. It is a way to take away some of the feel required and use the press as though it has a stop, making the process easier and more consistent.

One exercise you can do to train yourself on how much pressure it takes to use a LCD is this: Try to size a case to make the bullet light slip fit. I tried to make a case to use as maximum bullet seating length gage using an LCD. I wanted a case that would just be tight enough to allow the bullet to slip while chambering (without primer or propellant) but tight enough to retain that seating depth. Obtaining this neck tension is quite difficult, but not risky since all you have to do is apply full lever pressure to complete the sizing and try again with another case. This exercise will surprise you with how little lever pressure will size the neck enough to disallow pushing a bullet in by hand.

To deburr the collet, take a narrow strip of fine wet or dry paper and pull it around the inside of one of the petals of the collet and out the slots. Pull it back and forth to polish away the burrs. Repeat with the other 3 petals of the collet. This will prevent lines on the neck from the burrs at the slots of the collet petals. Lightly polish the upper part of the collet that rides in the upper angled part, and the recess in the mandrel holder. Lightly apply grease to those areas.

I've never had any problems with lack of neck tension or bullet pull and don't really understand how that would happen unless the brass is soft or hard. I can't imagine bullet diameters for a given caliber vary enough to cause a problem, but maybe they do. I did have problems with nickel plated brass dragging on the mandrel so I quit using nickel plated brass.

One thing I understand after studying this thread is that the mandrel doesn't drag on the case, but moves with it when the collets are actually touching the case. Since the mandrel has to slide on it's holder while the collet compresses the neck, maybe a smidge of grease on the mandrel where it rides in it's holder would be beneficial.
 
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Homerange - I can't see any way a Lee collet die has anything to do with the shoulder. The amount of case neck that gets sized is dependent upon how the collet portion of the die is machined. How deeply the die is screwed into the press, or how much the press arm is leaned on won't change that.
Consider two things:
When they are adjusted for a press to cam over, the pressure imparted onto a LCD is far more than one can apply with just a pull on the press lever. Even the size, twist and size again can't impart the same pressure onto the case like a cam over setup can.
Further, the collet itself uses the shoulder for leverage and nothing else so when using a cam over setup naturally there will be more force applied onto the shoulder.

This is not to say the shoulder can be 'bumped' with a LCD but case datum length can be maintained better by using the Valentine method.
All you have to measure this by is bolt lug friction, in that when using the Valentine method for setting an LCD, there will be less bolt lug bind than using the LEE setup method.
Sizing die dwell time should also be considered and just a few seconds pause between cases can change results especially if you infrequently or don't anneal.

Try it, you might be surprised.
 
The force applied when using an FCD die with cam over is dependent upon how far the die is screwed in. The Valentine method is to screw the die in just far enough to apply the right force when camming over. It is a delicate setup, but I can envision the rewards.

Lee doesn't offer this method because they are trying to keep the instructions simple. What they don't want is a situation where you cam over accidentally after already applying enough force to sufficiently resize the neck.

The base of the collet contacting the shell holder pushes the collet up, not the case shoulder. I don't see how a collet die could have any effect on a shoulder unless it was defective in dimension or used for the wrong cartridge.
 
The force applied when using an FCD die with cam over is dependent upon how far the die is screwed in. The Valentine method is to screw the die in just far enough to apply the right force when camming over. It is a delicate setup, but I can envision the rewards.

Lee doesn't offer this method because they are trying to keep the instructions simple. What they don't want is a situation where you cam over accidentally after already applying enough force to sufficiently resize the neck.

The base of the collet contacting the shell holder pushes the collet up, not the case shoulder. I don't see how a collet die could have any effect on a shoulder unless it was defective in dimension or used for the wrong cartridge.
Err well yes, but do you consider LEE has the shell holder base to datum SAAMI dimensions wrong for any caliber they make LCD's for ?
And of course the collet when squeezed against the mandrel doesn't also put some pressure onto the shoulder ?


For the 6 calibers I load with LCD's I use the Valentine method for all the larger ones when bolt closure issues start to show signs of being a problem.
The fact that an LCD works the brass only a fraction of traditional dies has my case life extended and without the need to anneal .....at all !
Case problems, I have zero.
 
If you have bolt closure issues with a neck die, it is time to use a body die. How you are rectifying close or short headspace (indicated not verified) with an LCD, I don't know. I can't see how an LCD could possibly shorten headspace when used properly.

A LCD, as with all neck size only dies and sizing. would appear to have little to no impact on headspace. A slight compression and drawing with friction sizing which is mitigated with good lube and carbide or titanium nitride bushings. I can't imagine why the Valentine method would fix a possible short headspace problem with your larger cases.

You can get the same results with Lee's LCD setup instructions as with the Valentine method, and apply the same force with either method. The Lee setup method requires ideal press lever pressure every stroke, the Valentine method just requires ideal setup, then every stroke is routine, and the pressure perfect only if the setup is.

The thing that keeps many users of the LCD out of trouble is that it is uncommon to apply too little lever pressure, and too great of pressure doesn't cause many problems up to popping the top of the die off. Too great of lever pressure could never cause neck brass to flow, you can't develop serious clamping force with that apparatus. With the LCD, any lever force beyond which successfully sizes the case, is too much. It seems that is what the Valentine method attempts to prevent.
 
No cam over....for many years now . No need to cam,at all. Lee gives simple instruction,because it really is that easy.
 
I use the LCD on my 223 bolt action brass. When sizing, I can feel the collet start to size the neck at about half way down on the lever, I then raise the handle and rotate the case 90 degrees and then lower the handle until cam over. I also turn the cap of the die to make small adjustments in cam over pressure.

This procedure gives me pretty much zero neck run out, no case growth, almost never have to trim, normal bolt closure and dozens of cycles on the brass. Neck tension is mild, but consistent and the groups on the target show it works.

I have annealed the brass occasionally, and could feel the difference while sizing, but it was totally unnecessary. As the brass work hardens the neck springs back slightly more, keeping the bullet seating pressure very consistent. My work hardened and sized brass measures about .0005 smaller than loaded, but the tension just feels right while seating.
 
Lee doesn't offer this method because they are trying to keep the instructions simple. What they don't want is a situation where you cam over accidentally after already applying enough force to sufficiently resize the neck

I've never used a Lee press so I may be off on this but as far as I know their presses don't cam over so that may be why they don't have instructions for a press they don't make.
 
TC260 - They have instructions for Lee presses and other than Lee presses for the LCD. 1-3/4 turns in following contact with shell holder for Lee presses, 2 turns for other than Lee presses. It says the extra 3/4 turn is to prevent cam over.
 
10-4, I've been using LCD's for so long I had no recollection of having ever gone by their directions but reading your post jogged my memory. I vaguely remember counting turms the first time I bought one, ripped a couple necks off the cases, threw the directions in the trash and found the Valentine article. All has been good since :D
 
Following Lee's directions has worked for me, as has the method described by Valentine. Back in the day, when I knew less and was more ham fisted, I set my collet die with a lot more cam over than was desirable or necessary which resulted in ribs on the necks of my .220 Swift case necks. They shot just fine. Never had a problem. It probably improved centering. Of course I don't do that any more. These days I either do it Lee's' way or set the die for the slightest toggle that can be felt. Both work just fine. I have done all of this with my Rock Chucker. I would be concerned about toggling a lightly constructed press because the mechanical advantage with RC style linkage becomes very great near the top of the stroke. If you look at Lee's presses it becomes obvious why they would not want you to toggle. On the neck tension issue, there is more to it than may be obvious to many. Some powders work better with more bullet pull. Another thing, sometimes having fine measuring tools makes us worry about things that do not show up on any target. Test and believe the results. You have plenty to worry about with things that actually do matter.
 
One thing about squashing the case neck walls on the mandrel is it seems to uniform neck wall thickness when you do a double squeeze say about 90 degrees or a little less. I use a very light cam over, it doesn't take a lot of pressure on new cases or freshly annealed.
 

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