neck turning Virgin or Fired brass

Discussion in 'Reloading Forum (All Calibers)' started by TackDriv3r, Mar 15, 2019 at 9:00 AM.

  1. TackDriv3r

    TackDriv3r

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    I am not so familiar with neck turning. I hope this gun nut ( me ) isn't a waste of your time since its been mentioned so many times on the internet.

    I have a K&M neck turning tool, and I have those stainless steel K&M mandrels ( .002" under bullet diameter ) , ( also a Generation II mandrel die with carbide mandrels ( .001" under bullet diameter ) is on its way here for expanding brass necks without the expander button on the sizing dies and a .0001" micrometer is on backorder ) and wanted to ask if it best to turn necks on fired brass or virgin brass? Doing this just to clean up high spots and improve run out issues, if any.

    I have the standard cutter, it won't say the degrees stamped on it, but it does cut into the junction of the shoulder,,,what degree would this cutter be? There are various cutters with different angles.

    I did a little test yesterday on a Hornady 6.5 Creedmoor virgin brass ( I normally use Nosler, but won't use them for testing ) , I full sized the brass case, then checked the CaseMaster for runout on that neck and it shows .004" runout, then I used the K&M mandrel to expand prior to neck turning , then I proceeded to turn the neck on that brass case using a drill and the K&M turner, I shaved off until I could see some high spots removed, stopped and cleaned up with steel wool, then rechecked runout, still .004",,,so back on the turner again, shaved off .002" as a test, and rechecked on CaseMaster,,,still .004" runout. What am I doing wrong?
     
  2. Preacher

    Preacher Gold $$ Contributor

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    Turn them new if you need to for clearance, otherwise turn them after they have been fired once..
     
  3. TackDriv3r

    TackDriv3r

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    Thanks for the response, would you have any idea why the .004" variance on the virgin brass after neck turning?
     
  4. Uncle Ed

    Uncle Ed

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    Your new unfired 6.5 Creedmoor brass has .004 case neck runout and turning the case neck will not make the neck concentric and have less runout with the case body. Meaning you made the necks thinner but neck turning does not correct neck runout in relation to the case body.

    What type full length die did you size the cases with, a bushing or non-bushing full length die?
     
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  5. TackDriv3r

    TackDriv3r

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    I used a Redding Type S full size die non bushing with the expander button
    .
     
  6. Fliers

    Fliers Gold $$ Contributor

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    New brass, I believe, has pretty tight necks. An expander ball on that will induce runout.
    Take that out and use just your mandrel instead.
     
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  7. jr600yd

    jr600yd Gold $$ Contributor

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    If your virgin brass has .004 runout neck turning wont help. Cull your brass and fire form. Remeasure after.
     
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  8. Uncle Ed

    Uncle Ed

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    Below I converted a standard Redding full length die by adding a Forster expander and spindle assembly. And having the Forster high mounted floating expander greatly reduced the neck runout in the Redding die. Why drag the oblong Redding expander with more surface area through the case neck and pull it off center.

    [​IMG]

    That being said you can take any resizing die and remove its expander and use a expander die and reduce neck runout. I prefer using a Forster full length non-bushing die with their high mounted expander and size the case once and get the same results.
     
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  9. TackDriv3r

    TackDriv3r

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    Thanks guys, I'll go ahead and remove the expander out of all my full sizing dies. My bushing dies do not have the expander since I removed them last week, still waiting for my Sinclair expander die with the carbide mandrels to size .001" under. Thanks folks for the advises.
     
  10. Joe R

    Joe R Gold $$ Contributor

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    I made this video just for you :).

    Joe

     
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  11. TackDriv3r

    TackDriv3r

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    Good stuff Joe, thanks.
     
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  12. paulT

    paulT

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    Thanks Joe, could you please post Link for neck size mandral expander die.
     
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  13. Joe R

    Joe R Gold $$ Contributor

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    Here it is http://036d541.netsolhost.com/porter/

    You're welcome. Did you find it helpful? 340 views and only 4 thank yous.

    Joe
     
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  14. Sixgun

    Sixgun

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    Don't bother checking run out on virgin brass. Just expand and skim up the necks. Done. Worry about concentricity after they're fire formed.
     
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  15. SPJ

    SPJ Silver $$ Contributor

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  16. earlcurtis67

    earlcurtis67 Silver $$ Contributor

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    Nice job on the video Joe. I agree with sixgun. I skim cut virgin brass but im running a sammi chamber. Also i run the brass through an expander mandrel first, then turn with a turning mandrel. E
     
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  17. Martin52

    Martin52

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    Thanks Joe, good video. One question, what diameter pin gauge are you using compared to the i/d of the resized neck to expand back up ? Is it just enough to touch the inside of the neck or 2-3 thou more ?
     
  18. paulT

    paulT

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    Hi Joe Posted Link doesnt seem to show the mandral expander die specs or how was made, Your video on neck tension and neck turning was very good and helpfull Thanks, pault.
     
    Last edited: Mar 17, 2019 at 9:20 AM
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  19. Webster

    Webster

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    I was going to comment on how I turn my brass but I think I would refer to the following tech article on this website.

    https://www.accurateshooter.com/technical-articles/reloading/complete-precision-case-prep/

    I reviewed Tony Boyers book and it seemed like to much wandering over several pages to follow. He needed to give short one sentance steps as far as sizing before turning. One good point is to measure the length of new or sized? cases for overall length. If they vary by more than 0.003" trim all to the shorest one. The reason for this is the turner stops cutting into the shoulder area by the end of the neck touching the shoulder on the mandrel. If the cases vary in total length the stop will cause a different cut into the shoulder on each case.
     
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  20. Rust

    Rust

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    I would recommend measuring your neck thickness variations before bothering to turn brass. I use a Sinclair neck turning tool with a dial indicator to measure neck thickness, the brass is sized and chamfered to prevent any burrs or dings from causing inaccurate measurement. The dial indicator is good for 0.001" which I find sufficient for my purposes since I run no turn chambers (smaller than SAAMI but not requiring neck turning with selected brass). If you are shooting SAAAMI spec chambers, anything better than .002" uniformity should be good to go.

    As mentioned previously, you will want to trim your brass to uniform length prior to turning. And turning will not straighten a case.

    IMO, turning brass is generally not required for a non tight neck chamber, and should only be done if the brass as measured requires it. Another solution is to just get better quality brass in the first place.
     
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