6 Dasher jump or lands?

Discussion in 'Reloading' started by Chrisjan, Jul 28, 2013.

  1. Chrisjan

    Chrisjan Member

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    Hi,

    I shoot 95gr Bergers, I currently jump 0.040. This load shoots 1.5” at 600 yards.
    This is a no turn, very tight neck with .002 neck tension.

    What is best?

    The start of ignition is most important, but with all factors equal. Is it more desireable to load against the lands, giving the powder more time to build up pressure and heat?
    Or having a jump and giving the bullet an easier start and letting the bullet enter the rifling at a higher speed?

    Thanks for the help.
    Chrisjan
     
  2. boomtube

    boomtube Well-Known Member

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    "Thanks for the help."

    The only help" anyone can honestly give you is to go test whatever you want to try, nothing about reloading for acccuracy is a given.

    If you're getting 1.5" groups at 600 yards it's unlikely you're going to do better. And you won't even do that again if you get a few puffs of wind on the range.
     

  3. Mikecr

    Mikecr Well-Known Member

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    +1 Boomtube
    Whatever setting shoots the best -is best. It's not predictable, but has to be determined locally.

    Why did you choose 40thou off? Was that determined to be best?
    If not, what are the chances that is best?
    I say low, but you may be luckier than I
     
  4. Gene Bland

    Gene Bland Member

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    If you are getting a 1/4 moa at 600 I would not change a thing. If you insist on changing extend out in .010 increments until touching. Keeping in mind that 1 bullit diameter in the neck is necessery for proper alighnment and neck tenchion. Jamming into the grooves may cause overpressure with your current load.gun)
     
  5. Chrisjan

    Chrisjan Member

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    [Why did you choose 40thou off? Was that determined to be best?
    If not, what are the chances that is best?
    I say low, but you may be luckier than I[/QUOTE]

    Hi Mikecr,

    Due to magazine lenth limitations, I had to start at ,010 off the lands. I then worked away from the lands at ,004 incremints. At ,040 it is holding vertical very well.

    It is just because on berger's website it is advised to try jump. But most posts on bergers seems to suggest close or in the lands.
     
  6. Mikecr

    Mikecr Well-Known Member

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    I'm glad you tested, but now I gotta ask:
    When you say "This load shoots 1.5” at 600 yards" are you talking about grouping, accuracy, or only a portion of them(vertical)?
     
  7. Chrisjan

    Chrisjan Member

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    Hi,

    This is on a 3 shot group in perfect weather, no wind at all and just after sunrise. So no mirrages. Total vertical is only half an inch
     
  8. boomtube

    boomtube Well-Known Member

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    "Keeping in mind that 1 bullit diameter in the neck is necessery for proper alighnment and neck tenchion."

    "Necessary"? :D

    You do realize there are several factory cartridges and many wildcats that have necks shorter than the bullet's diameter?