Partial full length resizing

Discussion in 'Reloading' started by winelines, May 30, 2009.

  1. winelines

    winelines Well-Known Member

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    I have read several posts where they indicated that, as an alternative to neck sizing, they would partially resize the case using a full length resizing die so that it would just bump the shoulder. What is the procedure for setting up the die to accomplish this?

    Thanks
     
  2. AJ Peacock

    AJ Peacock Well-Known Member

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    You need an ability to measure your shoulder to base length. Typically using a Caliper with a Hornady head space gauge attached to it's blade.

    Setting up the die is easy. Measure the length, resize and reset die until the appropriate amount of shoulder bump is achieved. I personally like .001" shoulder bump and 2/3 of the neck resized.

    AJ
     
    Last edited: May 31, 2009

  3. SES50

    SES50 Well-Known Member

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    What i have been usung is the redding competition shell holders. Basically what you get is 5 shell holders from -.002" to -.010" off of a standard redding shell holder. This lets you bump the shoulder back until it just fits into your chamber. I have had pretty good results with them.
     
  4. winelines

    winelines Well-Known Member

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    Thanks, guys. I think I understand both suggestions. I will give them a try.
     
  5. AJ Peacock

    AJ Peacock Well-Known Member

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    The comp shell holders definitely make it easy to adjust that last .001" or so (they are in .002" increments), but the process is the same, having calipers and the Hornady headspace gauge will let you replicate your setup from one reloading session to another.

    AJ
     
  6. Natty Bumpo

    Natty Bumpo Well-Known Member

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    I use a full-length die and keep screwing it down bit by bit until my case chambers without any resistance on the bolt. How is this different from using the headspace gauge to measure the amount I'm bumping the shoulder, other than giving me a number so I can say "I'm setting the shoulder back 0.00X inches." Isn't the object of either method to resize your cases no more than is necessary? I never thought of this as only "partially resizing the case."
     
  7. distantfoe

    distantfoe Well-Known Member

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    If a standard full length die is used and the shoulder is bumped, the whole neck has been resized. The only way that I know of bumping the shoulder and partially neck sizing is with the use of a bushing die.
     
  8. Limbic

    Limbic Well-Known Member

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    That's what I thought as well. I use a RCBS precision Mic to give me the headspace. I lower the die until i get .001 or .002 of bump. I'd be interested to see how many people use bushing dies and how many use expander balls
     
  9. winelines

    winelines Well-Known Member

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    I guess the twist to this that I forgot to mention is that the caliber is a .300 Wby, which is headspaced off the belt. I tried screwing out the sizing die until it seemed I am just starting to form the shoulder. I tried to use a RCBS runout guage to find the shoulder, but it is impercise at best. I guess I can use the lock ring to repeat the sizing from session to session. It loooks like I am resizing about 3/4 of the neck.

    I guess the alternative is the competition shell holders.
     
  10. AJ Peacock

    AJ Peacock Well-Known Member

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    Just ignore the belt and set the shoulder back .001" (essentially forcing it to headspace off the shoulder), I've been doing this for years with the 7RM (most accuracy nuts do the same thing with belted magnums).

    AJ
     
  11. AJ Peacock

    AJ Peacock Well-Known Member

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    Exactly, with a bushing die, you set the shoulder bump and then set the neck bushing to size how much of the neck you want sized.

    AJ
     
  12. BountyHunter

    BountyHunter Writers Guild

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    IF it is a FL size die with bushings. If it is NS, it will never touch the shoulder.

    BH
     
  13. AJ Peacock

    AJ Peacock Well-Known Member

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    Picky, Picky, Picky! :) But very correct. A NeckSize only bushing die won't touch the shoulder, must have a FullLength sizing bushing die.

    AJ
     
  14. winelines

    winelines Well-Known Member

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    Guys, thanks for all the good info!

    :D