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

[done111]

I like to use the Lee collet dies. I have noticed however that the bullets go into the brass just a little too easy. In comparison to virgin brass i have receive from Lapua, Hornady, and Peterson, I kinda think the Lee collet could put at least a little more tension on the bullet to get even close to them (maybe virgin brass is known to be tough to seat bullets in).

I had turned the mandrels in the past in a drill using sandpaper and then scotch bright, but never felt I was getting it turned to a consistent diameter all the way around and all the way down.

I just discovered Lee makes mandrels 0.002" smaller and ordered one for my 6.5 Creedmoor and 223 collet die.

I'm afraid they won't actually still have good tension as they are about the size as the ones I did homemade in the drill. Anyone using these notice a considerable difference in seating tension?

I do anneal my brass so I am hopeful my brass springback is pretty consistent. I understand one can expect 0.001" springback but haven't confirmed that myself.

I've heard of people rotating the brass an 1/8 turn and neck sizing again. Does anyone have any evidence that this process is worth adding to my brass sizing routine.

Thanks for listening and any lessons that can be given,

Don

 

[Dusty Stevens]

ditch the collet die and just use one quality FL bushing die. simplify your life and get whatever neck tension you want and dont worry about brass problems anymore

 

[done111]

ditch the collet die and just use one quality FL bushing die. simplify your life and get whatever neck tension you want and dont worry about brass problems anymore

I am wanting to keep the inside of the neck round and not push imperfections to the inner diameter of the neck. I'm not wanting to turn necks at this time. I'm also not wanting to pull a ball through the neck to final size the inner diameter. I like the idea of pushing the brass to a mandrel, just looking for a possibility of better ways to impliment the Lee collet. Of course, my way isn't necessarily the best way.

 

[Mikemci]

I chucked my mandrel in a drill press, set it to a low rpm and lightly held a 600 grit diamond sharpening stone against it. Got it close to the O.D. I wanted, then switched to a 1,000 grit.
Be sure you read John Valentine's article on how to adjust the die in your press properly. I just love my collet neck sizer!

 

[Toby Bradshaw]

Order a custom mandrel in whatever diameter you want. For $5 each, might as well order 2 or 3 different sizes.

https://leeprecision.com/custom-undersized-mandrel.html

I use Lee collet dies (and a body die) on my big boomer hunting rifles. They work like a charm for this purpose. I generally use a mandrel 0.003-0.004" under bullet diameter.

 

[done111]

Order a custom mandrel in whatever diameter you want. For $5 each, might as well order 2 or 3 different sizes.

https://leeprecision.com/custom-undersized-mandrel.html

I use Lee collet dies (and a body die) on my big boomer hunting rifles. They work like a charm for this purpose. I generally use a mandrel 0.003-0.004" under bullet diameter.

Thanks for the link. Good to know I can order custom sizes. I'm gonna see how the 0.002" undersized ones work first that I have on order. Being able to have a "set" of mandrels is a nice option for adjustment.

Don

 

[Flouncer]

ditch the collet die and just use one quality FL bushing die. simplify your life and get whatever neck tension you want and dont worry about brass problems anymore

Hoe does this change the diameter of the re-sized case neck around the bullet like a change in mandrel diameter of a collet die ???

I don't understand how this changes the neck diameter ??? It seems to shorten the neck length ??

http://www.redding-reloading.com/images/stories/PDFfiles/b-nkquickstart.pdf

 

[Homerange]

I chucked my mandrel in a drill press, set it to a low rpm and lightly held a 600 grit diamond sharpening stone against it. Got it close to the O.D. I wanted, then switched to a 1,000 grit.
Be sure you read John Valentine's article on how to adjust the die in your press properly. I just love my collet neck sizer!

This ^.

If you use a collet die with it adjusted to go over center it takes a bit of trial and error to get the neck tension just right. Using it like Lee say can be more 'foolproof' but either way if you've got the die set incorrectly you'll have problems with insufficient neck tension....annealed or not.

 

[Dusty Stevens]

Hoe does this change the diameter of the re-sized case neck around the bullet like a change in mandrel diameter of a collet die ???

I don't understand how this changes the neck diameter ??? It seems to shorten the neck length ??

http://www.redding-reloading.com/images/stories/PDFfiles/b-nkquickstart.pdf

a bushing squeezes the OD of the case neck to whatever size you want and that in turn changes the ID which changes bullet tension. the FL die part sizes the case back to whatever spec you get it made to or back to min saami spec if thats what you order (off the shelf dies). if you only neck size eventually your brass grows too much and you will end up with tight cases and a click upon opening the bolt. its always better to use one properly fit FL die to size your cases rather than a multitude of tolerance stacking dies. and most of the top shooters use bushing dies to adjust their neck tension- you have to adjust according to condition of the brass and atmospheric conditions, bullet size, powder lots, barrel preference, etc. the lee die is like a neck die- they seem to be a good thing in theory but after a while you'll have some kind of issues and after some investigating and a couple mystery brass problem posts here youll end up solving the issue with a good FL bushing die then no more brass issues.

 

[Bart B.]

the FL die part sizes the case back to whatever spec you get it made to or back to min saami spec

I've never seen any SAAMI specification for unloaded case mouth/throat diameter. All they show is the bulleted case. Bullets typically have a .003" tolerance.

As 30 caliber bullet diameters have a .002" (or more) spread across different makes and types, one diameter mandrel cannot be perfect for all. I'd bet 2 sheckles other calibers are similar.

 

[jepp2]

I've heard of people rotating the brass an 1/8 turn and neck sizing again. Does anyone have any evidence that this process is worth adding to my brass sizing routine.

The actual guidance by Lee is 1/2 turn. But this extra step isn't intended to provide further reduction in the case neck diameter. It is to potentially reduce the case neck TIR. If you get additional neck reduction, you aren't applying enough force to the collet.

I successfully use LCD on a wide variety of calibers. Might not be a popular input, but I have read the John Valentine summary that many subscribe to. I prefer to use the Lee instructions. I have never found the need to go to an undersize mandrel. The ONLY time I had an issue with neck tension was with brass that had necks that were very hard (hadn't been annealed). Since I began annealing (and not every firing cycle) I haven't had an issue at all.

But maybe I'm just living a gifted life where I haven't hit the combination of bullet diameters to cause a problem. I do keep records of what is happening to the case necks. So I know the fired neck OD, the neck OD after sizing and the loaded neck OD.

So questions I would have about your process: what neck tension is your new brass - 3 brands running? What neck tension is your LCD sized brass running with your modified mandrels? Are you sure your annealing process is achieving the desired result? How do you confirm?

Words like "kinda loose" and "I am hopeful my brass springback is pretty consistent" don't really give me confidence you have control of your process. Maybe you do, but you are questioning some things you could answer but haven't yet done so.

 

[JohnD]

Done111, how does your gun shoot? Let your target tell you if you need to make changes.

John

 

[Fotheringill]

OP-

Get custom mandrels from Lee .001 and .002 undersized. Total $10. See if results on target get better.

 

[BoydAllen]

Years back I was shooting a Swift and sizing with a Collet die. The loads were relatively mild, but the distances were not all that long and the accuracy was good. When I switched to moly coated bullets they were not secure in the necks due to the reduced friction so I ordered a smaller mandrel and that solved the problem. As far as end to end uniformity of the mandrel goes I would not be too concerned because the actual sizing takes place at a specific location on the mandrel and the brass springs back slightly when the pressure is removed. If you feel that the case is dragging or the neck is being enlarged as the case is removed from the die you can always make some clearance in the non working area of the mandrel. This clearance will not be critical as long as the diameter is slightly smaller than the working area.

 

[done111]

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

 

[Bart B.]

All 26 caliber bullets are not the same diameter. What one does Lee reference?

 

[Ggmac]

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

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

 

[Dusty Stevens]

I've never seen any SAAMI specification for unloaded case mouth/throat diameter. All they show is the bulleted case. Bullets typically have a .003" tolerance.

As 30 caliber bullet diameters have a .002" (or more) spread across different makes and types, one diameter mandrel cannot be perfect for all. I'd bet 2 sheckles other calibers are similar.

The part you quoted says nothing about case mouth- thats the part where i talked about sizing the case ( the fl die part) not the bushing part of the equation

 

[JohnD]

Yeah Don, your subject line kind of threw me-"Lee mandrel made to exact bullet diameter". Everyone of mine that I measured are .002 smaller than bullet diameter. They are all standard that came with the die. No wonder your bullets fit loose.

John

 

[Fotheringill]

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.