Neck Turning Brass

Discussion in 'Reloading' started by Mabia, Aug 28, 2013.

  1. Mabia

    Mabia Well-Known Member

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    For the people out there that neck turn your brass, what neck thickness are you ending up with?

    I have just turned enough to clean up my brass and ended up with about .012". Is this about normal?

    Randy
     
  2. Broz

    Broz Well-Known Member

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    I usually shoot for an 80% clean and yes .012" would be fine. My 6br some ends up at .011"

    Jeff
     

  3. AZShooter

    AZShooter Well-Known Member

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    I think most would agree neck turning can help make neck tension consistent with brass that has uneven neck wall thicknesses. 284 win brass comes to mind.

    As for what wall thickness the cartridge ends up with depends on the chamber reamer's neck diameter. I prefer to have .003" to .004" clearance per side for bullet release. I have a 30 BR reamer that is working with .001" clearance per side. IMO a tight release clearance requires diligence and attention to detail. Carbon must be removed with steel wool after every shot. I have also discovered after several firings/sizings that the necks must be turned again as they thicken slightly.

    If one decides to turn necks on a factory hunting rifle that already has more than ample neck release clearance the neck tension consistency might improve accuracy but the necks could split early in the life of the case. I know I am guilty of doing exactly that with my first attempts at neck turning for a large case neck clearanced 284 win.

    Skim turning and removing approximately 80% of the brass from the neck is the best approach for no turn chambers. Just realize the necks might be the first part of the case to fail.
     
  4. Bullet bumper

    Bullet bumper Well-Known Member

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    I invented a special technique for neck turning in a factory chamber called partial neck sizing . The reason I say I invented it was because I came up with it all by myself but others would have also done the same thing .
    For a bolt gun if you only size some of the neck and leave an unsized second shoulder . You will avoid all the negatives associated with neck turning in a factory chamber . Use a Lee collet die to size the neck with a washer over the case to shorten it. Use a Redding body die to size the remainder of the case when needed but it will never touch the slight second shoulder . It stays a neat fit at all times . If it drags when chambering shorten the unsized section a bit . The die system reduces case neck hardening and the partial sizing reduces stress on the case neck while expanding and keeps the case centred no matter what other sizing is done .
    I know 4 World champion shots that use this system .
    I load every bolt action I have this way and skim turn the necks on every one.
    Don't believe me ? Try it and see .
     
  5. AZShooter

    AZShooter Well-Known Member

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    Bullet bumper,

    It makes sense to leave a portion of the lower case neck unsized. The redding S bushing dies leave a small amount untouched but only the very bottom of the neck. I suppose it would be easy enough to adjust the S die so it sizes even less of the neck.
     
  6. Bullet bumper

    Bullet bumper Well-Known Member

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    Redding have left it that way because it's hard anyway to get a bush down all the way and not risk crushing the shoulder some , because the edge of the bushing has to have some arris on it anyway , it can't be a sharp 90 degree edge .
    However the small unsized section still helps and it does not have to be very long to give good results with neck turning . It is one of the reasons people get good results from the die , they are using partial neck sizing without knowing it . You can make it any length you want as long as chambering is easy and you get enough bullet grip for the ammo use .
    Many people will say the shoulder does all the aligning and it will not achieve anything but the fact is that sometimes people need to bump the shoulder back and size the body down to regain easy chambering so that can't be the same fit as you had before you bumped and sized it . However the second shoulder is NEVER sized so it reduces potential changes to alignment during the life of the case without the need to resort to complicated measuring tools to track sizing operations .
     
  7. DocB

    DocB Well-Known Member

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    Hello Jeff, BB, and AZS,

    For such a short thread there's been a ton of info here. I never cease to be impressed by the wealth of experience and knowledge in this group.

    I am a padiwan when it comes to reloading and am always eager to learn from the Jedi Masters of reloading that we have here to guide us. :)

    Questions I have are:

    When you state "80 percent" are you referring to 80% of the neck length or neck thickness?

    The partial neck sizing makes a lot of sense to me, albeit I am still a lowly padiwan. I use a Lee FL die and Neck Collet die and my 300WM is a 'factory' rifle.

    How much of the neck is sized in this process and how would you go about setting up the die to size just a portion of the neck

    When using a "washer", exactly what is it's purpose and where is it placed? I have seen 'shims' which are placed beneath the casing on the shell holder made by Innovative Technologies and specialized shell holders which are 'sized' to increase the shoulder bump. Is this also the purpose of the "washer" and how do you determine the thickness of the washer?

    One last question: What is meant by "skim" trimming? I have an idea what is meant but I'm just not sure.

    Ok, another question just popped into my head :rolleyes:: If you ream the necks in addition to neck trimming, would this process change?

    I am very grateful and appreciative to you 'Masters' for sharing your wealth of knowledge and experience as well as your time and patience with us 'padiwans' :D

    Thanks!!

    DocB
     
  8. AZShooter

    AZShooter Well-Known Member

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    I can address the skim turning or removing 80%. It refers to the amount of brass removed over the entire surface area of the neck, from mouth to shoulder with a neck turning tool. The idea is have the cases the same neck wall thickness for a more consistent bullet release.
     
  9. Bullet bumper

    Bullet bumper Well-Known Member

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    Skim turning 75 to 80% means you just take off as little as possible and if the missed sections on the case neck are only about 15 to20% of the total surface area then that's fine it is essentially straight now . As the case is fired more the neck may thicken a bit and another skim at the same old setting may clean them up more or even sometimes 100% .

    However you have to turn all the way down onto the shoulder and just skim the very start of the shoulder just a fraction to make sure you have gone the entire length of the neck . If you stop short you can ceate a dough nut .

    If you want to do partial neck sizing then you can not ever use a Full Length sizing die ever again . You have to separate the two sizing operations . 1 neck size die only and 2 Body die size .
    The Lee collet neck die is quite ok for the neck size operation and works better with a skim turned case . The washer is placed over the case to be sized when it's in the shell holder so when the collet skirt comes down onto the washer instead off the shell holder the effective sized length is shortened by the thickness of the washer . The washer has nothing to do with the things you mention , they are part of sizing for shoulder bump and head clearance. Nothing to do with neck sizing length which the washer controls . I have never done it with a belted case so some adaption may be required as I don't know how much room is around the case belt diameter when on the shell holder but I can't see a problem .
    This leaves the unsized section you want.
    Then you have to purchase a Redding body die for the cartridge .
    This is used when the cases start to get hard to chamber or at a certain number of firings that suits you .
    A body die does not size or touch any of the neck of the case so your slight second shoulder set up by partial neck sizing is preserved.
    If you can not buy a body die for your particular cartridge you can modify a Full Length die into a body die. By cutting the top off the die just a bit longer than the case mouth and drilling the neck diameter out to about .010 larger than the neck diameter of a fired case .
    For a 300 WM the Redding body die you need is number 75153 .
    Internal neck reaming can be done within this system ina factory chamber as there is no particular wall thickness required as there would be in turning for a specific diameter tight neck chamber . However skim turning and internal reaming is not such a good idea as it could leave the case neck too thin and increase neck to chamber wall gap even more which is what we are trying to regain with partial neck sizing and it's more prone to splitting .
    A good option is skim turn the necks and polish the inside of the necks .
    This can be done with an old worn bore brush wrapped in a small amount of fine steel wire wool and chuck it in a battery powered screw driver and run it back and forth inside the neck .
    I hope that answers your questions.
     
  10. DocB

    DocB Well-Known Member

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    Thanks BB!

    How do you determine the percentage of the neck to leave unsized when you partially size? Is it by trial and error or is there a minimum-maximum of case neck that you can leave unsized? From what I understand from your explanation this would equate to the thickness of the washer that is placed around the cartridge on top of the shell holder. Correct?

    Thanks for the info on the Redding FL Sizing Die. It will be in my kit asap. I already use the Redding competition seating micrometer die with the Lee Collet neck sizing die.

    Would it be possible to take pics of your process the next time you work up a load? I'm good with seeing and doing, lol!:)

    Again, I truly appreciate your help mate!

    DocB
     
  11. DocB

    DocB Well-Known Member

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    Sorry, I meant thanks for the info on the Redding Body Die.. my bad.

    DocB
     
  12. Bullet bumper

    Bullet bumper Well-Known Member

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    Correct , the washed sets the unsized length.
    It's mainly trial but no error , to work out whats a good length to leave unsized .
    It all depends on how much bullet grip you have and need to hold the bullet for a certain purpose. Neck tension requirement is different for different ammo use. The tension you would need to hand feed a cartridge one at a time is less than you would need to use a magnum cartridge through a magazine .
    A bullet needs to be kept straight at all times in the case during feeding as it could affect accuracy and safety if the bullet does not have enough grip .
    Start at 1/3 or less of the neck length leaving 2/3 for bullet grip.
    If you get any resistance to chambering that annoys you , then reduce the length more with a thinner washer .
    When using the Lee Collete die it is better to do two sizing pull downs . The second one at 90 degrees to the first . That is just rotate the case 90 degrees and size it again .
    Also using a press like an RC BS Rock chucker that goes over centre is the best way to use a Lee collet die to get a repeatable pressure on the case neck .
    I could take some pictures of sizing with the Lee collet die and washer if you like but not the whole process that I have outlined from the start of teh thread , that would take a lot of photos.
    I'll take some photos tomorrow ok that will make it a bit clearer .
     
  13. Gene

    Gene Well-Known Member

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    Most of these and other questions are covered in "Handloading for Competition" a 400 page book authored by Glenn Zediker. He has a unique style of prose, but is a knowledgable fellow.
    I have read the book at least 3 times and refer to it often.

    In addition, if you google "neck turning" on the internet, you will find more info than you can absorb in a year.
     
  14. Bullet bumper

    Bullet bumper Well-Known Member

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    Hope this helps .
     

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