Extreme Spread?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Firecat, Sep 20, 2010.

  1. Firecat

    Firecat Well-Known Member

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    What can be done to lower Extreme spread when reloading bullets? I took out my 300 win Mag and found that it had an ES of almost 100 FPS. I understand that this may be a very open question, but it is the only way that I know how to ask it. Thanks
     
  2. greener280

    greener280 Well-Known Member

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    What Load are you shooting? Powder type and charge, how far off the lands are you, ect.
     

  3. RockZ

    RockZ Well-Known Member

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    What bullet ,powder,primer
    dies -sizing and seating
    etc
     
  4. CA48

    CA48 Well-Known Member

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    Also what chrono you using.
     
  5. Firecat

    Firecat Well-Known Member

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    Here are the particulars

    300 Win Mag
    Ruger Hawkeye
    Nikon Buckmaster 3-9 x 40mm

    Remington Brass
    180 grn Sierra Spbt Gamekings
    72 grn IMR 4831
    CCI 250 Large Rifle Magnum Primers

    Chrony Alpha Cronograph

    Fired at 5900 feet elevation, temperature 75 Degrees

    Muzzle velocity ranged from 2912 to 2997 over five shots
     
  6. RockZ

    RockZ Well-Known Member

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    what's the overall length
     
  7. Firecat

    Firecat Well-Known Member

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    I am at work and not able to get to my notes for the COAL. I did work with it and found that the length that sierra suggested yielded the best groups though. So I loaded them at that length.
     
  8. RockZ

    RockZ Well-Known Member

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    did you try many different powder charges

    i will run some numbers on quick load
     
  9. MSU Marksman

    MSU Marksman Well-Known Member

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    You may also try different primers and a shorter COL.
     
  10. RockZ

    RockZ Well-Known Member

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    Remember the quickest way to reduce ES is by changing powder charges. If one powder doesn't work try another.
    You can really fine tune it with case prep, neck tension, sorting etc.
    But the biggest most drastic change is through the powder.
     
  11. Firecat

    Firecat Well-Known Member

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    Thanks for your replies. I did try several different powder charges when i was doing my original load development. Unfortunately I did not own a Chronograph at the time. I chose the the charge that yielded the tightest groups. This particular load is around 2.5 grains off of max. So fairly mild. I am considering trying a different powder like Retumbo or H1000. I also thought about Reloader 22. This is a hunting rig for late in the year so the extreme hodgdon powders have caught my attention because of their reaction to temperature change is so minimal.
     
  12. RockZ

    RockZ Well-Known Member

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    I ran some numbers on quickload and it looks like H4831or H4831SC will work better than IMR 4831.
    You get a 95-100% fill rate and good burn characteristics.
    H4831SC would be my first choice to try, that way you can stick to the extreme powders.
    Just work up a load that is in the 2900-3000fps range and work around that.

    Retumbo and H1000 is a bit slow for the 180gr.

    VVN560 is also a very good powder for the 180gr.

    H4350 may also work but you will only get about a 88-90% fill rate.
     
    Last edited: Sep 21, 2010
  13. Firecat

    Firecat Well-Known Member

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    Rockz, What is the quickload program that you are using?
     
  14. RockZ

    RockZ Well-Known Member

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