Measuring OAL to ogive?

Discussion in 'Long Range Hunting & Shooting' started by corey006, Aug 8, 2018.

  1. corey006

    corey006 Well-Known Member

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    I recently ordered a Hornady Bullet comparator, and the 6 caliber kit.

    Also got the OAL gauge and modified case.

    I will be loading Berger 168 VLD in 7mm Mag.

    Does the 7mm "collet" match the ogive of the Berger VLD ? Or is there a special collet for VLD bullets?
     
  2. Schnyd112

    Schnyd112 Well-Known Member

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  3. corey006

    corey006 Well-Known Member

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    So you have to to find the precise OAL where your bullet is touching the lands....then put the collet on bullet and then subtract distance you want your ogive off the lands?

    It would nice if someone made a collet for different VLD bullets?
     
  4. Schnyd112

    Schnyd112 Well-Known Member

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    Yup. That collet is just something that will measure the same spot on the bullet each time. All your adjustment will be relative to the modified case measurement with each bullet touching the lands.
     
  5. yobuck

    yobuck Well-Known Member

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    Back in the old days there weren't any of the wonderfull tools that we have the option of buying today. Yet proper OAL was important even then.
    So what was done was to take an empty and unprimed case, and seat a bullet long, and then insert it into the gun and close the bolt. That would seat the bullet by jamming it against the lands.
    Next step is place it in the die and turn the seating stem down to touch the seated bullet, then back off and turn it in a turn or so deeper.
    Remove the round from the press and use a match to smoke the bullet only. Then reinsert the round back into the gun and look for rifleing marks on the bullet. Continue to turn the stem down and reinsert
    the resmoked bullet until the marks barely go away.
    Keep the cartridge as a gauge for that bullet for future die settings. Nothing to buy as nothing is needed. Use calipers for deeper seating depth from the touching depth just established.
     
  6. cohunt

    cohunt Well-Known Member

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    I was wondering--since there are differences in tolerances--which do you find to be more accurate when shooting, measuring to the "ogive" with the comparator, or measuring to the tip of bullet (c.o.a.l)-since non of the seating dies seat by using the tip of the bullet there always seems to be differences in OAL

    I have found differences in the bullets over all length, but also difference to the base to ogive measurement of the individual bullets too

    you could actually make an "ogive measuring tool" yourself, the true ogive is just where the bullet finally reaches full diameter.

    yobuck-- you could also use a sharpie instead of smoking--thats how I used to do it
     
    just country likes this.
  7. Schnyd112

    Schnyd112 Well-Known Member

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    This is how I was taught. Was having some odd things happening with my new rifle so I bought the Hornady tool. I can say that my numbers using the guess and check smoke method were right on with my measurements with the Hornady tool. Takes some practice to recognize what you are seeing but damn if it doesn’t work just as well.

    Cohunt- I feel I get better measurements measuring the “o-give” with that nut. With a Forster seating die I can get pretty consistent depths, .002-003” difference from longest to shortest most times. Neck tension and brass prep have been big in keeping the difference low.
     
    Last edited: Aug 8, 2018
  8. just country

    just country Well-Known Member

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    morning, yo buck is right. I use this method for many years.
    each bullet depending on the maker has a different ogive.
    cohunt with the magic marker r very correct. justme gbot tum
     
  9. corey006

    corey006 Well-Known Member

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    I am going to try this method.

     
    louis f likes this.
  10. Rum Man

    Rum Man Well-Known Member

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    Thanks for posting this !
     
  11. yobuck

    yobuck Well-Known Member

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    This would be the best imo, it does show a more expensive die than many of us use, but no reason a standard die couldn't be used also. The basic idea is the same, just use the gun for the measurement,
    no special cases to buy for each cartridge you load for.
    Yes, a sharpie can be used in lieu of a match, but I just prefer using a match.
     
  12. corey006

    corey006 Well-Known Member

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    I was lucky enough to pick up a Redding 7mm comp full set years ago on eBay for dirt cheap.

    I just ordered a VLD stem(but not sure if even required.)

    I plan on testing a few of the sizing dies to see which produces least runout.

    I am leaning toward Lee collet and bumping shoulder back with Redding Body die and using Redding Competition seating die.

    Not a fan of traditional sizing dies as they can produce runout in case necks...
     
  13. yobuck

    yobuck Well-Known Member

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    Thats true, and if your into trying for perfect loads, then follow your own instincts.
    Regular old fashioned dies aren't to be laughed at however from that standpoint. Seating the bullet in steps and rotating the case as you go seems to help, rubber O rings can help also.
    But when hunting, wind and tree limbs are more apt to be the problem, and the best remedy is very simple.
    Keep lead in the air till its over.
     
  14. esshup

    esshup Well-Known Member

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    I use the Hornady lock and load set. I purchased a tap and the correct sized drill bit from McMaster Carr to make my own modified cases. The case base to lands/grooves will change with the different bullets that are used, even in the same caliber. To me, maybe my thinking is flawed, but here's what I do.

    Use the lock & load tool with the bullet that I am going to be using. Get the dimension in that particular rifle. Write it down on the load data sheet. Then use the same lock & Load tool to measure the loaded cartridge minus "X" thousandths to get bullet jump. Shoot for group size and when I am satisfied I write that info down on the same load sheet. I save that bullet I measured with so I can use the same tools to chase the lands later.