Following FL bushing sizing with expander mandrel dwell time

Discussion in 'Reloading Forum (All Calibers)' started by SGK, Mar 14, 2019.

  1. SGK

    SGK Silver $$ Contributor

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    I see a good number of people recommending following a bushing sizing with a 4-5 sec dwell time in an expander mandrel, the aim being consistent 'neck tension'. Without custom mandrels this constrains the tension to 1 thou. I'd love to hear further thoughts on the topic...
     
  2. Dusty Stevens

    Dusty Stevens COVFEFE- Thread Derail Crew Gold $$ Contributor

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    You can do whatever dwell time makes your seating force read consistent
     
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  3. AJC

    AJC

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    Is this a spinoff of joe salts die dwell time.
     
  4. Willie

    Willie Silver $$ Contributor

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    I hold it at a 5 count, but don't know that it makes a big difference. There is gonna be a variance in springback anyway. What a mandrel does do, is direct springback inwards, toward the bullet. Can't prove it, but that seems to benefit neck tension. I need to get a force dial seater, one of these days.
     
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  5. Puzzaz01

    Puzzaz01 Gold $$ Contributor

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    That'll definitely tell you what you need to know.

    Darrin
     
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  6. SGK

    SGK Silver $$ Contributor

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    I guess my first question is whether this is good practice (bushing size down and expander mandrel up). I'm currently loading for .223 Rem. My (rather crappy) Hornady ELD-M 52 gr bullets measure 0.2235". I've turned my Lapua cases to a high side of about 0.013". I was using a 0.248" bushing to target 1-2 thou neck tension. The bushing produces/targets a 0.248-0.026 = 0.222 ID and the expander mandrel will increase that to 0.223 leaving rather little neck tension.
     
  7. Webster

    Webster

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    There should be no affect due to dwell time. Appears to be a made up thing. People will swear they see an affect but the copper industry has spent a lot of time studying this if for no other reason loss of switch contact pressure.

    https://www.copper.org/applications/industrial/DesignGuide/performance/tempstress03.html


    1 RELAX.JPG

    From this chart you can see 1 hour at 20C no change in relaxation. Ten hours a little change.

    https://www.copper.org/applications/industrial/DesignGuide/performance/
     
    Last edited: Mar 15, 2019
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  8. dkhunt14

    dkhunt14

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    That's why they make different sizes of mandrels. Size the case a hair smaller then needed and slightly expand with a mandrel to even them out. Matt
     
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  9. SGK

    SGK Silver $$ Contributor

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    I've only seem 1 per calibre and each 1 thou less than nominal. So .223" for 22 cal.
     
  10. hogpatrol

    hogpatrol Gold $$ Contributor

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  11. Dusty Stevens

    Dusty Stevens COVFEFE- Thread Derail Crew Gold $$ Contributor

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    And porter precision products offer one that you can get mandrels for $3ea and can get them in any dimension you want
     
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  12. Joe Salt

    Joe Salt Silver $$ Contributor

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    AJC What I do Is Size them twice, up once spin 180 and size again. Now I also use a little tighter bushing like MATT said and then us an Ex pander.

    Joe Salt
     
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  13. AJC

    AJC

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    I watched your video and found it very interesting. Currently trying a five count in the die. Dont have pin guages yet to go the other way.
     
  14. TrxR

    TrxR

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    Where do i find this die? I cant seem to find a link to one.
     
  15. SGK

    SGK Silver $$ Contributor

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    Link?
     
  16. Joe R

    Joe R Gold $$ Contributor

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    I made this video just for you :) . Good luck,

    Joe

     
  17. Joe Salt

    Joe Salt Silver $$ Contributor

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    Wrong Joe I'm Joe Salt!

    Joe Salt
     
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  18. Dusty Stevens

    Dusty Stevens COVFEFE- Thread Derail Crew Gold $$ Contributor

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