A question about bumping the shoulder?

Discussion in 'Long Range Hunting & Shooting' started by WildBillG, Sep 18, 2019.


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  1. Orange Dust

    Orange Dust Well-Known Member

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    This does get your attention when you are paying between 2 and 3 dollars per piece of brass for sure!!!
     
  2. WildBillG

    WildBillG Well-Known Member

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    I am out nothing if I try this shoulder bump method am I. As of right now I have to FL size my friends 300WM brass any way. The way I have thedie setright now is just touching the shell holder and brass is easy to reload. From what I have read I will find a tool around the house and start bumping the shoulder back.
    I will have to worry about neck tension and precise seating and alingment later on. We have had some good and bad groups but have been playing with powder and bullet seating depth thus far. Thank you all for the help. It was my hope when I started this thread that shoulder bumping would mean I could turn the die out more. The important thing is that I learned some thing.
     
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  3. 2C/1H

    2C/1H Well-Known Member

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    Well said and spot on
     
  4. robert l

    robert l Well-Known Member

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    Ok then about how many chamber reamer companys are out there? Because if you have say 4 shops making reamers then the chambers should be all over the place like they seam to be? I shoot the 338 edge and nowing its a wild cat that should mean the chambers should be alot closer because of the lack of shops making the reamers.
     
  5. Orange Dust

    Orange Dust Well-Known Member

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    I really dont think i have been clear. I dont think you need this die if you are running a hot 65000psi magnum. The primer pockets will expand before the beass wears out. The .002 bump is the recommended amount for minimual stretch above the web. 0 and .001 are fine too as long as it will chamber in your gun. The idea behind the bump die is to eliminate having to fl size after a couple of loadings just neck sized. In either case you want to set back the shoulder a minimual amount just so the round will chamber. Shoot for .002 max if you are measuring. Dont overthink this. Hope this is a better explanation. If you want to play with a new die, get a sinclair neck expander and some mandrels. Disable the expander in your sizing die. Expand the necks in the sinclair die. This will likely tighten groups at LR, but it will also most likely lower youe ES on velocity.
     
  6. WildBillG

    WildBillG Well-Known Member

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    Ok so one more question here I resized some 257 Wby brass in my FL die just touching the shell holder and it would not chamber. Neck sized it would. I had to turn die down quite a ways to get the brass to chamber what was causing this situation.
     
  7. Orange Dust

    Orange Dust Well-Known Member

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    Squeezing the sudes
     
  8. robert l

    robert l Well-Known Member

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    Sounds like you should keep going down a quarter turn at a time until the brass will chamber.
     
  9. WildBillG

    WildBillG Well-Known Member

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    I did do that not in quarter turn much smaller and they did chamber. I wish now I would have seen how much of a shoulder bump it was.
    Orange Dust I under stood what you were saying and thank you for your help.
     
  10. ShtrRdy

    ShtrRdy Well-Known Member

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    That's where you can use a measuring tool to see where the shoulder is after firing and where it is after resizing.

    If you measure where the shoulder is after firing be sure to push out the primer to avoid its influence on the measurement.
     
  11. L.Sherm

    L.Sherm Well-Known Member LRH Team Member

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    A 1/4 is a ton, that could easily be .010.
    I go no more than 1/16 -1/32 at a time.
     
  12. WildBillG

    WildBillG Well-Known Member

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    L. Sherm that is about what I did turn the die. Those threads on a die are pretty coarse for sure. My fear at first was will these ever chamber again not a good feeling with Weatherby brass.
     
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  13. Alex Wheeler

    Alex Wheeler Well-Known Member

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    I did not read all the posts in this thread but here is what you need to know about sizing. Measure the shoulder diameter before and after sizing, same with the widest point above the extractor groove. I like to see .002-.003" reduction in shoulder diameter and about .001" in base diameter. Bump the shoulder back .002" or so and you will never wear out a piece of brass, EVER. You need a comparator to measure the shoulder bump. This holds true for small 6mm cases in 1000yd Benchrest rifles through 338 lapua improved cases. Top accuracy and case life.
     
    Last edited: Sep 25, 2019
    L.Sherm likes this.
  14. Triple BB

    Triple BB Well-Known Member

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    Easiest way I’ve found on getting proper head space is using a set of Redding competition shell holders. Broz on this site narrates a video on YouTube that makes it so easy, a cave man could do it...