How to determine best distance from lands

Discussion in 'Reloading' started by fireroad, Aug 25, 2009.

  1. fireroad

    fireroad Well-Known Member

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    I recently read a post on this forum (or possably another one) where someone described a good technique for determining the best distance from seating the bullet off the lands. Basically, they said to take the bullet and powder you plan on working with and load it at the minimum recomended load. I believe he said start with the bullet .005 off the lands, then decrease the length until you find the group that shoots the best. When you have done that then start working increasing the powder until you achieved your desired results.


    Do these numbers sound right to you guys...starting at .005 and working closer? Would there be any reason to start out farther or go out farther?
     

  2. boomtube

    boomtube Well-Known Member

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    The numbers are okay, but work further off the lands, not closer.
     

  3. fireroad

    fireroad Well-Known Member

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    Intersting, I always thought the ideal distance from the lands was somewhere between .002 and .005, but you're saying it should be .005 or greater (.006, .007, etc)?
     
  4. trebark

    trebark Well-Known Member

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  5. fireroad

    fireroad Well-Known Member

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    Thanks 280fan (my favorite cartridge as well). My numbers where way off, I should have said adjust by increments of .002 to .005, not that actual distance from the lands. I'm guessing the berger method will work with any bullet brand?
     
  6. woods

    woods Well-Known Member

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    IMO you are still a decimal place off. Certainly it is OK to start at .005" off the lands but you will not see any significant change in group size when moving only .002" at a time unless you do a LOT of shooting. A more normal change in seating depth when looking for a seating depth would be .02" at a time. For instance .005" off, then .025" off, .045" off etc. Or at least vary it by .01" at a time.

    Many bullets, especially the Barnes copper bullets, need to be started at .05" off and never get closer than .03" off. You will have a hard time regulating the seating depth to have a variance of less than .005" from bullet to bullet, much less .002".

    IME when you get closer to the lands than .02" then you need to get absolute control of seating depth by consistant inside neck dimensions and bullet grip and by using a very good competition seater. I have yet to find a rifle where you could not find a good load by starting at .02" off and then finding the powder and powder weight the rifle prefers. Some rifles like Weatherby's and RUM's can be very accurate even when seated .275" off the lands.
     
  7. boomtube

    boomtube Well-Known Member

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    Seating at or into the lands, or even close, is a BR techique. But their rifles and their cases and their bullets are different from ours, so are the techniques needed. Attempts to use BR methods for our stuff is a mistake.

    The BR concept of seating close has been repeated so often it has taken on a "conventional wisdom" life of its own but is badly misapplied for the rest of us. It's primary purpose was/is to retard bullet movement and improve ignition/burn with softly held bullets, but common "logic" got around to saying it helped center bullets into the bore. There is no data I'm aware of to support that to be true in our loosely chambered store bought rifles. So, I wish we could drive a stake in that idea's heart and get rid of it completly, 'cause it's NOT true for factory rifles - or very rarely so - and it's not needed with our high bullet seating tension!
     
    Last edited: Aug 27, 2009
  8. cstilt

    cstilt Well-Known Member

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    I just loaded up several rounds using the article that 280fan posted. If all goes well, should be trying them out tomorrow. Hardest part for me being new to reloading was finding exactly how far to seat the bullets to touch the lands. My loads tonight didn't start touching the lands, just needed to know for a reference.

    To find the touching lands point I made a slit on each side of the case neck and inserted a bullet seated way too long. Then put a drop of oil on the ogive of the bullet to help keep it from sticking. I did that 3-5 times on 5 different bullets to get a good average. Then used that as my max distance with that bullet. After that I checked to see if that length would cycle through the magazine. Oddly, I tried using a marker to coat a bullet to start but it gave different readings compared to bare bullets.

    boomtube, where in NC are you? I just moved to TN and am taking up LR hunting (3-400 yards for me) and would like to know where I could practice at some extended ranges. Farthest near me here in Johnson City TN is 300 yards and you have to be a member to the club.