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9mm changing OAL?

Discussion in 'Reloading' started by ignantmike, Mar 14, 2010.

  1. ignantmike

    ignantmike

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    o.k i'm having an issue loading 9mm.....i seperated the brass by brand....i'm using a lee single stage press and dies....both new when i bought them....i'm loading 124gr fmj armscor bullets.....the problem is my OAL keep's changing?....i cleaned the shell plate and the area it seat's to....i'll get some that will measure 1.143 to 1.130....i have it set to 1.135????....when i load 10mm using the same press it stay's right on......any info would be great.......thank's mike
     
  2. robin303

    robin303 Helicopter Nut

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    Mine varies also. It is worse when I do 147 and HP. As a joke I measured 5 different brands of factory ammo and not one is really consistent. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:eek:ffice:eek:ffice" /><o:p></o:p>
     

  3. FiremanMike

    FiremanMike Way too busy

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    I'm getting the same numbers with my LCT... not a big deal..
     
  4. tlafrance

    tlafrance Missing AZ

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    No biggie. I get +- .005 so I set my OAL to 1.130 and carry on. Variation in rim thickness can do this.

    Tom
     
  5. WRXcelration

    WRXcelration

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    i have mine set to 1.115 +/- .005
     
  6. ignantmike

    ignantmike

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    thank's guy's....thought it was me....i found it wierd because my 10mm load's are consistant....guess the 10 brass is better
     
  7. BigDog[RE]

    BigDog[RE] NRA Member

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    Make sure the inside of your seating die is clean, sometimes you get a build up gunk in there. Also if your seating die comes with different seating plugs, make sure you are using the one the fits the bullet profile the best.
     
  8. Bettershotthanu

    Bettershotthanu

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    Best anwser yet.
     
  9. hoffy

    hoffy

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    What BigDog re said + if you are using a separate taper crimp die make sure there is not a bullet stuck up in there. I have been reloading for 30 + years and last year had an issue with 45 acp loads varying , I thought it was the seater, and then began cussing the press, and was shocked to find a bullet jammed up in the crimp die, knocked it out and back to a thousandths or two max variation. The seater die can really become a problem if you use cast and bullet lube gets gunked up in there.
     
  10. Randy from Kansas

    Randy from Kansas

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    Yes I agree
    I would like to add that your seating die is pressing against the profile of the bullet if you are using a die with the hole in the center of the plug. And you are measuring the over all length you can get different readings.

    Measuring off the Ogive would be the most accurate way to measure your loaded ammo. Even if the bullet is pointed the ogive of the bullet is what touchs the rifling and the tip of the bullet length really does not matter just as long as it functions in the magazine and firing.
     
  11. PCJim

    PCJim Senior Member

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    What has already been posted already should pretty well sum up your COL variance. I would also expect that if you measure the length of those bullets, you'll find a similar variance.
     
  12. GioaJack

    GioaJack Conifer Jack

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    Actually in most bullet designs, (if we accept that there are three separate ogive classifications with sub-categories of nose design within those classifications), the ogive of the bullet never touches the rifling.

    The exception to that would be what's referred to as a 'tangential' ogive where the beginning slope of the bullet starts just in front of the actual bearing surface, (driving band, if you will).

    The more common usage of the term ogive usually refers to that point where the bullet starts to slope in at the point where the bearing surface stops... that point being of smaller diameter than the bearing surface and hence not engaging the rifling.

    Some bullets, such as a true wadcutter design have no ogive, the entire bullet is a bearing surface... assuming it's not a bevel base. (The term 'ogive' technically means 'arch' and obviously a wadcutter has no arch whereas even a semi-wadcutter design has a portion of the bullet smaller than the bearing surface protruding ahead of the bearing surface.)

    Paying particular attention to ogive design probably had more application in rifle loading than in handgun cartridges... with some exceptions such as the Contender.

    What's this all mean... probably not much for most of our applications but there's no NASCAR on today and I'm bored as hell. :supergrin:

    Jack
     
  13. PCJim

    PCJim Senior Member

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    Me, too.:whistling:
     
  14. dudel

    dudel

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    You missed F1? You heathen.

    Don
     
  15. WRXcelration

    WRXcelration

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    It was great to see Schumacher back ( hes always been my fav) but there wasn't much action, I think everyone was expecting Schumi to charge to the front and win. I didnt expect Ferrari to finish 1,2
     
  16. GioaJack

    GioaJack Conifer Jack

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    Formula 1 is for wussies... if it doesn't have bump drafting it might as well be ballet. :whistling:

    Jack
     
  17. ignantmike

    ignantmike

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    thank's again for clearing it up for me.....also, i don't use a seperate crimp die.....i have the lee 3 die set.....it didn't come with different seating plug's....so i have the one sent with the set....and yes the die is clean....i checked it last night....i have only loaded about 50 round's with it so far.....
     
  18. MrOldLude

    MrOldLude

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    I've had good consistency w/ my anniversary kit. With a clean die, after I dial in my COL, I always give the round an extra stroke or two to make sure I'm seated. Repeatability has generally been +/-0.005"