Run out

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Tim Behle, Feb 2, 2003.


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  1. Tim Behle

    Tim Behle Well-Known Member

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    I've been asking this same question, several times a year, on this and other boards. Where in the hell have you all been?

    I just "tuned" the RCBS FL dies as instructed above. The result is 30 pieces of brass all less than .002" most in the .001"-.0015" range. Nearly all of these had been tossed aside due to excessive run out. Mostly in the .004"-.006" range.

    I don't remember how much run out I had in the brass before putting it though the Neck sizing die. But I know most all of it came out .004"-.005" out of round. I didn't use it very long before putting it back in the box and setting it on the shelf. If you were wanting to buy it, you're too late. I traded it this afternoon for 300 pieces of 200 grain semi wad cutters for my 45. I think I got a great deal, at least I'll use the wad cutters. [​IMG]
     
  2. kraky

    kraky Well-Known Member

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    Tim--just curious if you used my method or a combination of what was posted by all. Thanks Kraky
     
  3. Tim Behle

    Tim Behle Well-Known Member

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    Kraky,

    I pretty much just used the directions you gave, and "floated" the expander to the center. I had already tried the "O" ring, and didn't have anything on hand to polish the expander ball.

    Getting one badly out of round wasn't something that happened often, but once I had gotten a piece of brass out of round, it seemed nothing I could do would straighten it back out. So it got tossed into a bag of bad brass. Thinking one day, I'd learn how to fix it. [​IMG]

    I guess this was just a case where persistence paid off. I just had to keep asking the question until someone slipped up and revealed the magic secret [​IMG]
     
  4. Brent

    Brent Well-Known Member

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    When you all measure runout, do you indicate off of the bullet nose an 1/8th to a 1/4" behind the tip, up next to the neck or somewhere in between this. An apples to apples comparison with everyones runout numbers is only likely to happen if we all are indicating just off the neck by about the same amount, true?
     
  5. kraky

    kraky Well-Known Member

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    I usually go 1/2 way from the case mouth to where the bullet starts to taper towards the tip. Better said 1/2 the way up the shank??
     
  6. 4mesh063

    4mesh063 Well-Known Member

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    Kraky,

    That would be called 1/2 the way up the bearing surface. Farther and you are on the Ogive. Now, if the Ogive meets the bearing surface at a tangent, that's a "tangent ogive". If the ogive is an arc that would continue beyond the bullet diameter (if it continued), that is a "secant ogive"

    Just a little semantics.
     
  7. kraky

    kraky Well-Known Member

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    There has been so much RUNNOUT QUESTIONING LATELY (on all the forums) that I'm getting too lazy to type out my explanation. Maybe if I was good On a computer I could carefully write up my idea and somehow transfer it to the forum every time the question appears--which lately seems to be about every 5 days. All I know is it makes sense and it works. Glad you understood it. d kraky
     
  8. Guest

    Guest Guest

    Tim,
    To answer the question that you asked "what to do with the ones that don't meet your critera". This is simple; straighten them up!
    I straighten all mine up to within 1 thous. by inserting the bullet into a hole which is drilled into a piece of UHMW (like the white cutting boards). Just a little "tweak" and the bullet is aligned with the case.
    I check all mine with the NECO gauge and have beening doing it this way for about 8 years now.It works great.
     
  9. MAX

    MAX Well-Known Member

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    I measure run out about 1/8" ahead of the case neck +/- depending on cartridge. I've not tried straightening after the fact but do index the rounds and find that when oriented the same even .005"+ RO can shoot good groups, just not exactly where you want them. [​IMG] I segregate depending on cartridge and application, usually in increments no larger than .001", ie. (.000-.001") then (.002-.003). Seldom use more in the field and usually trash a case with more than .003 on the second go round. Maybe somebody should write a book on the subject so we'd know what we're supposed to be doing... [​IMG]
     
  10. BountyHunter

    BountyHunter Well-Known Member

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    Brent

    Jim charges $35 for his conversion using redding or wilson neck dies.

    If you want down on the shoulder such a neck size and shoulder bump there is only one die that does that. Neil Jones makes a custom FL shoulder bump die ( $175 for die and his custom bushings $14). He needs three pieces of brass that have been fired in "your" gun 3 times. Now if you are doing a wildcat with shoulder blown forward and out, he will make the die a Neck size only to allow you to fire some brass. Send the brass and die back to him and he changes the insert in the die to shoulder bump at no extra charge. Only guy around that does that and his dies are the Rolls Royce of dies for 1K BR shooters but still at reasonable prices.
    \
    Good Luck

    BH
     
  11. Brent

    Brent Well-Known Member

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    Thanks Bountyhunter. Is he using a reamer or a lathe to cut the dies?
     
  12. ross spagrud

    ross spagrud Active Member

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    One other note......be sure to check runout
    on some rounds AFTER you have cycled them
    through the magazine (if you have one).

    Ross
     
  13. Brent

    Brent Well-Known Member

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    Bountyhunter,

    I talked to Neil Jones today, he'll be making the dies for me. He does cut them on the lathe and has reasons for not using a reamer. The die will be set up to full length size the body .001" and use the shoulder bump and neck size inserts. Look forward to giving them a try.

    Thanks.