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Thread: Lee Collet Die Adjustment

  1. #1
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    Lee Collet Die Adjustment

    Hey guys, does anyone have any special tips for properly adjusting a Lee Collet Neck Sizing Die? Do you just color the neck with a permanent marker and keep screwing the die down until it is sizing the better part of the neck or is there a special set-up needed?

  2. #2
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    For non Lee Presses Such as my RCBS Rockchucker, 2 turns past the mandrel
    touching the shell holder. Use the lock nut to index the 2 turns then tighten down. 1 Turn for Lee Presses.

    I've tried marker doesn't seem to help I've had to replace the collet the mandrel and now the aluminum cap stripped out the top. Insides do not slide freely and the mandrel must be removed for cleaning with a combination of a vice then a dowel and hammer.

    If adjusted, after sizing little ridges appear after use where the collet squeezes the brass to the mandrel. Use an extra fine steel wool for 2-3 turns to polish the necks after use.

  3. #3
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    It does not size like that , it squeezes in on a central mandral. The only way you can reduce the length of neck area sized is by placing a machined washer over the case onto the shell holder. The thickness of the washer is the length of reduction.

    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.
    *****
    Last edited by J. Valentine; 03-14-2008 at 03:10 AM.

  4. #4
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    Quote Originally Posted by DaRealViper View Post
    For non Lee Presses Such as my RCBS Rockchucker, 2 turns past the mandrel
    touching the shell holder. Use the lock nut to index the 2 turns then tighten down. 1 Turn for Lee Presses.

    I've tried marker doesn't seem to help I've had to replace the collet the mandrel and now the aluminum cap stripped out the top. Insides do not slide freely and the mandrel must be removed for cleaning with a combination of a vice then a dowel and hammer.

    If adjusted, after sizing little ridges appear after use where the collet squeezes the brass to the mandrel. Use an extra fine steel wool for 2-3 turns to polish the necks after use.
    I think you are using way too much force to size.

  5. #5
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    Nope the Die body wasn't machined to specs I believe.

    Why? Because the die wouldn't work properly when adjusted as mfg instructions and yes I used to place white lithium greese on it before I replaced the mandrel and collet with new ones.

    Now, I have to replace the cap if possible but the collet will no longer come out of the body so wood dowel and plastic mallet time.

    deburred the collet and polished the mandrel worked ok for awhile slight mis-adjustment the press would cam over at the top.

    Must have got a bad one. It happens.

    Is it possible for brass to lose springiness or tension so that it is no longer sizeable?

  6. #6
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    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 .
    Use the same process for normal neck sizing also.
    I have five Lee collet dies and I use two quite regularly and I have never had that kind of failure.
    If you buy a new one , I will be interested in hearing if the problems persist.
    A faulty piece of gear is always a big possibility in this game.
    One problem is that the manufactures instructions are wrong! If you use my instructions I feel with a new die you will be much better off.
    Last edited by J. Valentine; 02-27-2008 at 06:45 PM.

  7. #7
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    John Valentine,

    Can I occasionally show your excellent description on adjusting the Lee collet die to acquaintances - with (totally) due acknowledgement?

    cheers

    John

    PS: Why didn't I see it before I learned the hard way?

  8. #8
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    Quote Originally Posted by John Kielly View Post
    John Valentine,

    Can I occasionally show your excellent description on adjusting the Lee collet die to acquaintances - with (totally) due acknowledgement?

    cheers

    John

    PS: Why didn't I see it before I learned the hard way?
    Yes you are welcome to use it that is what it is posted for to help other shooters.

  9. #9
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    John,

    Good work. I have used collet dies for many years set up like you said. They worl very well. Like you said, Lee's instructions really are not the best way to set them up. Also a proper locking ring like the Forster ones are a big help, the Lee ones should be thrown away !!

    The set up is one of those things that is very simple to show somebody but hard to actually describe, you did a good job.


    Mr Viper, if you blew the alloy cap out the top you used FAR to much force. Used properly the amount of handle pressure on the press is very small. In a cam over press you can darn near do it with just the weight of the handle if you let it fall a short way. The handle with just "click" over centre as the case neck is sized. Jammed collets, blown tops and marked mandrels are class ic examples of an abused and misunderstood collet die. Ignore your own method of setting up and read and understand what John has written.

    You don't need to alter the handle pressure to gain more neck tension, once the neck is on the mandrel you can't push it any more. If you want more neck tension just polish the mandrel down a smidge. For a 223 collet die I have three mandrels, one standard and a -1 thou and a -2 thou for greater neck tension.


    The collet die is about the best way to size a case neck for a non neck turned/tight necj chamber and may be better than bush dies in a lot of applications. I'd be tempted to try one with my bench rest 6PPC if I could be bothered sizing the neck and body in two operations every loading !!

  10. #10
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    Hey guys, I just received my Lee Collet dies and gave them a try. I did as John instructed and ran the press to the top of the stroke and screwed the die down till it touched the skirt. I slowly turned the die down and kept running a case up until it seemed like the neck was sized enough to hold a projectile. I found that by the time I was getting enough sizing taking place that I had to have the die adjusted so that I needed a considerable amount of pressure (say 20 lbs ?) Anyhow, I also found that the amount of tension created by the collet die was considerably less than the amount of tension my RCBS expander ball neck die creates. When I seat bullets on my .220 Swift using my RCBS neck die, I have a hard time pulling them off with a plier, but when I seat one with the collet die, it comes off relatively easy with a twist of my plier. (yes I know using a plier on a projectile ruins it). Anyhow, is this normal?

  11. #11
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    Quote Originally Posted by Swifty View Post
    When I seat bullets on my .220 Swift using my RCBS neck die, I have a hard time pulling them off with a plier, but when I seat one with the collet die, it comes off relatively easy with a twist of my plier. (yes I know using a plier on a projectile ruins it). Anyhow, is this normal?
    Swifty,

    You're a precision scientist after my own heart.

    We were chewing over this fact a couple of years back & came up with a couple of theories:

    • The Lee doesn't use as much neck tension as the standard dies do, so release tension might be lower. But we were all converts, so it wasn't an issue.

    • Conventional expander balls aren't at the high end of engineering finish, so maybe dragging one thru the neck roughs up the throat causing extra & quite possibly inconsistent tension.

    In your case, does the 220 still have thicker necks than the average 22 case, which might just result in more tension with the conventional system than if the same ball were dragged thru a .223 case?

    John

  12. #12
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    John,

    In response to your question about my neck thickness, yes I am using a group of brass with unusually thick necks. So when I think of it, your theory makes alot of sense.

  13. #13
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    Quote Originally Posted by Swifty View Post
    Hey guys, I just received my Lee Collet dies and gave them a try. I did as John instructed and ran the press to the top of the stroke and screwed the die down till it touched the skirt. I slowly turned the die down and kept running a case up until it seemed like the neck was sized enough to hold a projectile. I found that by the time I was getting enough sizing taking place that I had to have the die adjusted so that I needed a considerable amount of pressure (say 20 lbs ?) Anyhow, I also found that the amount of tension created by the collet die was considerably less than the amount of tension my RCBS expander ball neck die creates. When I seat bullets on my .220 Swift using my RCBS neck die, I have a hard time pulling them off with a plier, but when I seat one with the collet die, it comes off relatively easy with a twist of my plier. (yes I know using a plier on a projectile ruins it). Anyhow, is this normal?
    The neck tension sounds about right. What kind of press are you using ?

  14. #14
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    I'm using an RCBS Rockchucker

  15. #15
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    Quote Originally Posted by Swifty View Post
    I'm using an RCBS Rockchucker
    An RCBS Rockchucker is very good for a Lee collet die.
    Are you sizing to a point where the press goes over center and kinda locks the handle inplace . Just like BJS6 is doing.
    Your post does not give me that impression .
    If you are using just handle pressure against the die without it going over center then you have no controll over the size pressure , no stopping point .
    If this is the case then go back and readjust the die a small amount at a time untill it starts to go over center while resizing a case and the handle locks in place.
    Then try a projectile in the case . If it needs extra sizing from that point only move the die a very small amount at a time.
    If it stops going over center you have gone past the sweet spot.

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