Neck turning

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by sakofan, Jan 20, 2004.

  1. sakofan

    sakofan Well-Known Member

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    I have a K&M neck turner that I rarely use.
    Basically, I see no difference in accuracy between brass that has been turned, and that brass that is "factory". Run out remains basically the same on turned brass and unturned brass.

    I will occasionally take a "bad" case, one that keeps giving me bullet run out of .004 or more, and it does seem to help some. I guess.

    My question is this. Why should I be turning necks? What benefits should I see when the necks are turned?? And most importantly, how should I be turning necks?? How far down the case neck??

    Heck, maybe I have been doing something wrong all the while. Iam sure I have..sakofan..TIA [​IMG]
     
  2. Casey

    Casey New Member

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    sakofan,

    There was a time when I meticulously prepped cases for my hunting rifles/cartridges. I don't anymore. I would sort cases by weight and/or volume, drill the flash holes, uniform primer pockets, measure the thickness and diameter of the rims (and this can make a difference in the WEIGHT of a case--but has no bearing on the VOLUME--something to think about when we sort cases by weight), check runout to ungodly tolerances, turn the necks and neck size only.

    Today I still will sort cases by weight, but only to throw out really, really bad ones (my paramenters are much wider now, deburr the flash holes, and PARTIAL RESIZE. If we are talking about hunting rifles with normal chambers, partial resizing correctly may be one of the more important steps in accuracy--in chambers that are chambered to accept all the factory rounds from different manufacturers. This includes custom barrels
    on hunting rifles.

    Now back to neck turning. Those hunting rifle chambers have necks that are generally large enough that turning them just doesn't make a difference. But I have an Ultra Light Arms custom rifle that does like to shoot neck turned cases. Many of these high dollar custom hunting rifles will produce amazing groups--but with the ammo they were developed and chambered for (ie. Fed Gold Medal Match, Black Hills, etc). These rifles need those "cutomized" cases to shoot handloads well.

    The bottom line? I found that I hurt or made no difference in accuracy in most of my hunting rifles by turning the necks. Runout in neck and loaded rounds is important, but we can measure things so accurately with our tools these days we have a tendency to "over" focus on these things. Something I have to constantly remind myself: The benchrest world pays a lot of attention to these things because they have super custom, super tight fitting chambers with super finicky rifles/loads built to each shooters ideas of what makes accuracy--these things make a difference under those conditions.

    Casey
     

  3. Michael Eichele

    Michael Eichele Well-Known Member

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    The biggest reason I neck turn is to have 1, a concentric alignment of the bullet and 2, to have the same neck tension on each bullet. For typical hunting its not neccesary. If you want the kind of accuracy to kill small targets way out there, the more quality case prep the better. Neck turned and neck sized cases with primer pockets uniformed and flash holes deburred is the differance between a .75 MOA load and sub .5 MOA loads. At 600-1000 yards, that makes a HUGE differance.

    Ask your self how far do you want to shoot?
     
  4. Varmint Hunter

    Varmint Hunter Well-Known Member

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    In a factory rifle it is rarely worth the trouble to turn necks. There are so many variables when shooting factory guns and barrels that any gain in consistency would be lost within the many other unaddressed things that enhance accuracy.

    When turning necks for a factory saami chamber, you should only turn enough that you clean up 60-70% of the case neck. If you take off brass all the way around than you took off too much. The neck should be cleaned from the case mouth to the neck/shoulder junction.
     
  5. sakofan

    sakofan Well-Known Member

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    Thanks fellas, alot of good wisdom in all the responses.

    I love this website/forum, because you get informed, practical answers, all the time..sakofan.. [​IMG]
     
  6. Triple BB

    Triple BB Well-Known Member

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    Here's a question about taking off too much metal. I turned all my cases with a K & M. I think I was probably in the 60 - 70% metal removal. On some, I did did take off metal all the way around the neck, but not necessarily all the way down the neck. After you fire that turned case, isn't expansion and resizing going to bring things into a more consistent concentric fit in your chamber? My point is, if you took off a bit too much metal from turning, won't it be a better fit after sizing for the next firing? Just wondering...
     
  7. Varmint Hunter

    Varmint Hunter Well-Known Member

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    IMO if you haven't turned the necks from the case mouth to the neck/shoulder junction then yo haven't accomplished much. You will also have created varying neck tension along the neck. I haven't a clue what that does for accuracy.
    When turning necks you should turn them down along their full length, and a slight mark on the shoulder is a good indication of that. Notice I said "slight".
    Another thing that may be worth mentioning, that I have never seen posted on the boards; It is sometimes necessary to get a cutter blade in your neck-turner that matches the angle of your case shoulder. Some blades can not be run down to the base of the neck without cutting into the shoulder. 40 deg shoulders normally require a blade that is cut to an angle that is intended for these cases.isn't expansion and resizing going to bring things into a more consistent concentric fit in your chamber?

    "isn't expansion and resizing going to bring things into a more consistent concentric fit in your chamber?"
    No, not in my opinion. Firing and resizing is not going to iron out a bad case. A concentric chamber and quality, concentric dies will help maintain concentricity in a uniform case.

    VH

    [ 01-20-2004: Message edited by: Varmint Hunter ]
     
  8. Michael Eichele

    Michael Eichele Well-Known Member

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    TripleB,

    If you do not turn brass off all the way down, then after firing and resizing, that untuned brass is now on the inside of the neck. This is called a donut. It will be detrimental to your accuracy. [​IMG]

    [ 01-20-2004: Message edited by: meichele ]
     
  9. Triple BB

    Triple BB Well-Known Member

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    Sorry, I didn't clarify well enough. They have been turned all the way down the neck. On a few cases, metal was taken off all the way around and all the way down the neck. On the rest of the cases, metal was taken off all the way around the neck but only in certain places on the neck. On some it might've been in the middle or top or bottom. Maybe that clarifies my original question. Thanks
     
  10. Budman

    Budman Well-Known Member

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    sakofan
    Do you sort the cases first by neck concentricity first to determine what needs turning. I use a mic-4 gauge from sinclair and anything over .002 dosn't go any father. then I just clean them up 60 to 70% cut. Last night I worked on some Win 300WSM shells and the body concentricity was so bad on this batch of brass that 27 of 100 would not even go on the sinclair turning mandrel. The neck concentricity wasn't that bad but the whole shell was out of center. I was rather upset over the quality of the brass so I didn't take time to check them on the neco guage and will order norma brass today.
     
  11. sakofan

    sakofan Well-Known Member

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    Budman, I have a RCBS Case Master that I like pretty good. Good tool for measuring bullet runout and such. I have heard that the Sinclair is superior to the RCBS.

    I mostly just resize, use my K&M Expandiron, and seat them with a Forster BR die.

    I can usually get bullet run out down to about .002 or less for the most part. I feel that is largely due to the Forster dies and the Expandiron. If I get a bullet with .004 runout or more, I will try the neck turner. But, I havent noticed alot difference afterward. Maybe shaving a .001 or so off the bullet runout.

    Like I said, Iam not sure Iam doing my part though. Maybe I should run all the cases through the Case Master before I load them. I think that is what you are doing.

    I also use standard brass. No Norma, Lapua, and such. Win., Fed., etc.

    When you say, 60%-70% cut, are you refering to the lenghth of the neck, from the case mouth to the shoulder, or the actual amount of brass you are cutting "into" the neck??

    Thanks for all the responses. I might figure this out one day!! [​IMG] ..sakofan..
     
  12. Budman

    Budman Well-Known Member

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    sakofan
    Cutting 60-70% of the neck I am refurring to cutting or removing that amount around the neck (total circumference) all the way to the shoulder and just onto the shoulder. The sinclair tool has the cutter shaped to make this cut when set up properly. Different shoulders need different cutter but there are only two. One for 30 and one for 40 degree shoulders. You will not remove the same amount of brass on all shells and some shells will get cut more towrads the top,middle or bottom of the neck depending on how concentric the shell was to start with. By measuring first try to find a few shells with little to no gauge movement. What I was told was to find some flat linners or as close as possible on the gauge. Set cutter to remove 60 - 70% on these shells. This may ruin your best shells though if you don't get the cutter set up right at first. If you have all the shells separated for neck concentrecity to start with you will see how the brass is removed as you progress through the shells. Hope this helps.
     
  13. sakofan

    sakofan Well-Known Member

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    Thanks Budman. You explained it very well.

    I might look into the Sinclair guage as well.
    I have heard from virtually everyone, that the Sinclair "does more, better" than the RCBS. Great, I "get" to buy anougher stinking tool [​IMG] ..LOL..sakofan..

    I want to hit the guy in the mouth that told me I could "save money by reloading!!" Sure glad I started though!!
    [​IMG]

    [ 01-21-2004: Message edited by: sakofan ]
     
  14. Guest

    Guest Guest

    be careful of the guage for the turners.I have a problem with the guage not being true to the thichness I want so I went to a Ball mic from sinclair and will just use the guage for rough neck thickness and use the ball mic for more percise measurements.

    I have to turn my necks about three times because of the thick brass of the 338 lapua case once I reform my brass. then the brass is about 20 to 21 thou and I have to turn it to 11.5 thou.