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"Bulging" 9mm case and Lee Loadmaster auto-indexing

Discussion in 'Handloading and Reloading' started by malpais, Mar 18, 2012.

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  1. malpais

    malpais Member

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    Referring to this thread:
    http://www.thehighroad.org/showthread.php?t=642942

    The verdict as I understand is "it's ugly but it's ok", unless the bulge is uneven and that indicates tilted bullet during seating.

    What bothers me more than the aesthetic is this: I have the *exactly* same issue using Lee 9x19 carbide dies, and I have noticed the bullet even without applying crimp, is already seated very tightely.
    I am new to reloading, but correct me if I am wrong - this will lead to higher pressures. Or?
    Edit: I am getting the same kind of bulge using once-fired Geco cases.

    Also, those who have a Lee Loadmaster can perhaps answer this: is the auto-indexing just that badly designed or does it have to be set up in some special way? After watching videos on Youtube that deal with auto-indexing the main problem was that the indexing "arm" as does not catch the "slide" which pushes the indexing rod out on the downstroke.
    I have loosened the bolt hodling the carrier (the one on the bottom, where the operating lever is connected) and adjusted turned the carrier as far clockwise as I can and re-tightened it. The indexing rod's plastic piece is pressed snugly against the surface that it slides along... but still the indexing is a hit-and-miss process, unless I press manually on the indexing rod forcing it to be pushed out by the "ramp" it slides against on the downstroke.
    What am I doing wrong?
     
    Last edited: Mar 18, 2012
  2. wanderinwalker

    wanderinwalker Member

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    First off, welcome to the board!

    Second, I can't help with the Loadmaster indexing issues.

    Third, if your 9mm reloads are coming out with an "hourglass" shape, that's OK. It isn't the crimp that holds the bullets tightly in place in a case, it's the neck tension of the case. Adding lots of crimp to a bullet/case that isn't tight to begin with does nothing to keep the bullet in place. In a semi-auto round like the 9mm (or .45), all the "crimping" step really does is iron out the flare you had to put in the case to get the bullet to seat.

    If you've posted pics before and been green-lighted, your rounds are probably coming out fine. I know my 9mm reloads frequently have the "bulge" where the bullet is seated and they have for probably 10k rounds. Never had a problem with them this way.

    Oh, and the bullet has to be seated "tightly" to provide resistance for the ignition of the powder. And to resist being pushed back in when it is chambered.

    (Now if you were talking Magnum revolver rounds or lever-action cartridges, the crimp does serve to keep the bullet in place in addition to the neck tension. But that's just confusing the matter.)
     
  3. bds

    bds Member

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    Welcome to THR and reloading.

    The slight bulge you see is normal for reloaded rounds as resizing die reduces the case neck smaller than the diameter of the bullet. When the bullet is seated, dimension difference between the reduced case neck and the stretched brass where the bullet is seated shows this differential as case bulge. To me, this bulge shows evidence of a good neck tension that holds the bullet (but you should still do a QC check and test the neck tension - l either push on the bullet against the bench top and/or feed/chamber from the magazine by manually releasing the slide). If you are using larger than jacketed diameter plated/lead bullets, this bulge will be more prominent.

    What's more important is whether your finished rounds freely drop into the chamber of the pistol barrel with a "plonk".

    Winchester 115 gr FMJ (.355" diameter) with .375" taper crimp
    [​IMG]

    Berry's MFG, Speer Gold Dot HP, MBC RN/SWC lead bullets with .376" taper crimp
    [​IMG]


    As to crimp. The crimp does not produce neck tension. For semi-auto cases, taper crimp is used (not roll crimp that's used in revolver cases) so that case neck edge/mouth can headspace on the chamber. I typically use .020" added to the diameter of the bullet that will return the case neck flare back to flat (depending on the variation of case wall thickness by head stamp, this may add slightly negative taper crimp, which is OK for me).

    Drawing not to scale
    [​IMG]
     

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  4. JLDickmon

    JLDickmon Member

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    Two of the best explanations of that phenomena I have ever read.
     
  5. JLDickmon

    JLDickmon Member

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    It's kind of a mickey mouse design. How old is the set-up? It maybe so worn there's no fixing it.
     
  6. malpais

    malpais Member

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    Thanks a lot for the explenation. After somehow miraculously stumbling on the previous topic on the same issue I actually felt a weight lifted from my shoulders :) At the worst I thought the dies I got were not 9mm or just made not to spec... phew.
    So basicly a "light" crimp after seating to get the neck "un-flared", and it's good to go?

    This is actually the reason why I asked if I should apply any crimp after that, or not. The reason is that if say I crimp the bullet in a non-sized case, to the extent that the bullet neither moves or rotates, it is EASYER to get it out with a bullet puller (hammer) than the case that is hourglass-shaped and has no crimp what so ever.
    Frankly, after the bullet is seated in such tightely sized case I am afraid to damage my bullet puller... yes, it sits that tight in the case. The last thing it would do is move backward when chambering, because if you look at the pictures you can see that further seating into the case would require just as much and more force, as the case would be stretched open by the bullet.

    Your advice has helped me a lot though, so thanks. This is my first ever reloading so I am doing "dry runs" (no powder and primers) of the press and ironing out whatever issues I get.

    Brand-new out of the box! I already broke the original black plastic arm that was screwed on the indexing pin, and put the more translucent one on which seems to take more abuse.
    I would guess it is something benignly simple I am missing out here in the design of the press.
     
  7. bds

    bds Member

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    Yes and as long as the finished rounds fall in to the barrel chamber freely with a "plonk" and fall out of the barrel when turned upside down.

    And you also need to determine the Max and Ideal OALs of cartridge that will work well for your pistols.

    Max OAL is the cartridge length that the bullet nose will not hit the start of rifling when fully chambered and Ideal OAL is the cartridge length that will reliably feed/chamber from the magazine when the slide is manually released (without hand riding the slide).

    Ideal OAL
    is the longest cartridge length that will work well for your pistol to build more consistent chamber pressures sooner when the bearing surface of the bullet engages the rifling. More consistent chamber pressures decrease shot group size and improve accuracy.
     
    Last edited: Mar 18, 2012
  8. greyling22

    greyling22 Member

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    check out loadmastervideos for a good how-to on setup and operation. I've reloaded a lot on all lee presses, and without the videos I never would have got the loadmaster working right. I can't visualize "a plastic arm screwed on the indexing pin." Nothing on my press seems to match that description. Maybe the flipper on the indexing rod?

    9mm is a tapered cartridge and you get a wasp waist effect when you reload them. It's normal. If you ever start reloading 30 carbine it will do the same thing. I think it has to do with the carbide sizing ring in the die undersizing the whole case because it is a short ring at the bottom of the die instead of a tall full case length tube, but I can't prove it and could be wrong.

    I started only sizing my tapered cases (9 and 30) down about half way instead of all the way. They still chamber fine in my guns, require much less effort to size, and don't give such a wasp waist effect. I assume it might theoretically extend case life by not working the brass as much, but most splitting happens at the neck, which is still getting worked.
     
  9. bds

    bds Member

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    Although the seated bullet "may" appear to be tight in the case neck, bullet setback may occur during feeding/chambering of the finished round as the bullet nose bumps on the ramp while being pushed from behind by the slide. If bullet setback occurs, this will seat the bullet base deeper in the case neck and increase the chamber pressure when powder ignites. This is not good, especially when you are using near max/max load data.

    "Trust but verify" :D

    For me, the best way to check for neck tension and bullet setback is to measure the OAL of the cartridge before and after feeding/chambering the round from the magazine.

    Adequate neck tension should result in no bullet setback or very minute decrease in OAL (say ~.001"). If you notice significant bullet set-back, I would investigate what's causing the decrease in neck tension.
     
  10. brickeyee

    brickeyee Member

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    Or non-uniform case wall thinness.
     
  11. malpais

    malpais Member

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    Sorry... yeah, that thing :)
    As I said the press is brand new and I did follow indexing troubleshooting instructions that I have seen in some Youtube video. I assume Loadmastervideos is either a site or a youtube channel so I will google it.

    Roger that. In that case I assume a half crimp should suffice.
    I actually used the information datasheet that followed with the press or dies, picked out a maximum seating depth according to powder and bullet weight (Frontier bullets, I believe 124gr and N330).
    So maxing out the OAL will produce more even pressure... ok, I will try that.
    Besides the issues with the press I thin I have it all figured out.

    The shooting iron is a G17, by the way. What else, he he :)
     
  12. greyling22

    greyling22 Member

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