Turret press cause accuracy problems?

Discussion in 'Reloading' started by jakesparents, Jun 3, 2010.

  1. jakesparents

    jakesparents Member

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    May 5, 2010
    I have an older Lyman turret press and have noticed that when sizing or seating that it will have a little bit of flex in the head when under pressure. Does that slight angle cause any problems as far as runout in the case and/or seated bullet, or does the die keep it all in line? I don't currently have a way to check the cases or cartrigdes for runout.

    Thanks!
    Andy
     
  2. J E Custom

    J E Custom Well-Known Member

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    Yes it can cause problems in many area's but it can be fixed.

    After tightening the hold down bole on the turret place a dial indicator base on the body of the
    press and the dial plunger on the turret and zero it.

    Try sizing a round on the press to see how much movement you have.

    If you have any then place a washer type shim under the hold down bolt and tighten it untill
    you can just barely turn it and check it again. if there is no movement your home if there is movement then the turret needs to be bushed for a tighter fit.

    Even the most rigid presses may have a slight amount of flex if the fit of all parts are not
    perfect and can cause concentricity issues.

    All presses should be checked if there is a run out problem.

    J E CUSTOM
     
  3. jakesparents

    jakesparents Member

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    Thanks lots! I was thinking that might be the case. I will try that fix and see if I can get it corrected.

    Andy
     
  4. boomtube

    boomtube Well-Known Member

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    "Turret press cause accuracy problems?"

    I too have an older Lyman turret press and eventually bought a single stage O press for just that concern. I've since learned the major "problem" the turret caused was in lengths, not the angular displacement.

    Dies do hold cases quite straight during both sizing and seating but the slack necessary to allow the head to turn has more spring than many of us prefer. That spring accounts for small variations, case to case, in both FL shoulder set back and, sometimes, in OAL. (I've found Lee's "Dead Length" seaters, properly used, are great for seating in turret presses!)
     
  5. jakesparents

    jakesparents Member

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    I have the lee dead set dies too, and they have given me very consistent OALs. I set the depth of the die in the press so that it just pushes snug against the die when it the handle breaks over center. That seems to work well. I have the Lee collet neck sizing die too, and am not quite sure I have that performing just right yet. I have my press clamped to my desk, just no space for a separate workbench. It worked well till I started using the neck size die. I think I will have to come up with a bit better idea for that. I noticed the Lee full size die takes considerably more effort than my older RCBS die does. Not sure why. I think I might use the RCBS to full length size it. It was working just fine.

    Andy