Tiny flash holes...

Discussion in 'Handloading and Reloading' started by 1976B.L.Johns., Sep 19, 2021.

  1. Ray P

    Ray P Member

    Joined:
    Jun 2, 2004
    Messages:
    448
    Location:
    NM
    Not 9x19, but igman 223 has flash holes smaller than my depriming pin, and frequently off center. Lost too many priming pins (Lee universal deprimer) in those things, so any that show up in my range brass now go straight to recycle bin.

    Igman headstamp is "IK" or, in this last batch, "IK 21"
     
    reddog81 and GeoDudeFlorida like this.
  2. LiveLife

    LiveLife Member

    Joined:
    Jan 10, 2010
    Messages:
    27,102
    Location:
    Northwest Coast
    Perhaps because they had crimped primer pockets?
     
  3. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    Data! Hurray! Where does it come from and is it for 9mm or everything?
    Now, does this source say why?
     
  4. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    Excellent point, but I asked first (well second actually) way back with comment 10 or so. Comment 8 by @Rule3 was the first.

    I simply want some data to support that flash hole size has anything to do with performance in 9mm. Would make things more consistent was the original thesis.

    ‘cause I’m telling you, I don’t mind spending more time getting to know my cases by first name (as I think you artfully put it) if there is some return.
     
  5. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    So there is no data.
     
    Rule3 likes this.
  6. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    So there is some data…could interfere with decapping. I’ve never had it happen with my Lee nor Redding due to small hole size, but several others here apparently have. But still no performance relationship that we know of.
     
    jmorris likes this.
  7. jmorris

    jmorris Member

    Joined:
    Sep 30, 2005
    Messages:
    18,445
    Performance wise, I doubt there would be a lot of difference but I have never tested any side by side.

    It’s been almost 20 years ago now but when I tested the large/small flash hole 45 ACP brass, the larger flash hole gave slightly lower ES/SD but I only tested with one powder/charge weight and the sample size wasn’t very large. Close enough to the same that I felt there was no need to sort them from one another.

    Same goes for SP pocket 45 ACP, no need to change the load but do need to be separated due to the mechanical issues of trying to put a large primer into a small pocket.
     
    Last edited: Sep 23, 2021
    merlynski, LiveLife and CQB45ACP like this.
  8. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    Hey thanks.
     
  9. LiveLife

    LiveLife Member

    Joined:
    Jan 10, 2010
    Messages:
    27,102
    Location:
    Northwest Coast
    I can do a myth busting thread on this if you like.

    Just had my first cataract surgery done on my left eye yesterday with Vivity multifocal IOL with 100% light transmission and things are looking good (literally). Surgery on my right eye is in 3 weeks so I may get a chance before or after but I have following myth busting/testing threads planned:
     
    Last edited: Sep 23, 2021
    JimKirk likes this.
  10. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    Good grief man, that’s painful. All I was asking about were performance issues related to OPs 9mm question.
     
  11. LiveLife

    LiveLife Member

    Joined:
    Jan 10, 2010
    Messages:
    27,102
    Location:
    Northwest Coast
    Actually no pain. But I am definitely "seeing the light". :D

    No issues. I like doing myth busting threads for retirement. Besides, what else am I going to do in retirement other than build wife chicken houses and pick up cute puppies (Puppy #4 this year) while buying more gun stuff?

    [​IMG]
     

    Attached Files:

    • p1.jpg
      p1.jpg
      File size:
      396.5 KB
      Views:
      55
    reddog81, JimKirk, Swampman and 2 others like this.
  12. RashQuestion

    RashQuestion Member

    Joined:
    Apr 5, 2021
    Messages:
    76
    God Bless You.

    Thanks for all you contribute here!!!

    You are a better man than I. I hope to be more like you when I grow up!!!
     
    GeoDudeFlorida likes this.
  13. Rule3

    Rule3 Member

    Joined:
    Jan 26, 2010
    Messages:
    8,437
    Location:
    Florida
    ?u=https%3A%2F%2Fmedia4.giphy.com%2Fmedia%2F7XoTE46IZsSY0GVlxZ%2Fgiphy.gif
     
  14. LiveLife

    LiveLife Member

    Joined:
    Jan 10, 2010
    Messages:
    27,102
    Location:
    Northwest Coast
  15. GeoDudeFlorida

    GeoDudeFlorida Member

    Joined:
    Dec 1, 2020
    Messages:
    3,874
    Let us know how your testing turns out. And don’t forget to document your data. :thumbup:
     
  16. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    I’ve outsourced it.

    And in the interim I’ve drilled out, chamfered, and just generally deburred the flash holes of 100ish 45ACP. Seriously. (And soon my shooting will be much improved.)
     
  17. Ranger99

    Ranger99 Member

    Joined:
    Mar 2, 2021
    Messages:
    468
    Location:
    Republic of Texas
    I use a similar tool of a different make
    on brass I've not loaded. For those who
    never used one, it goes inside and
    cuts any burrs where the flash hole
    was punched. One time deal
    There's more slivers hanging from a
    case than you might think
    20210918_171831.jpg
     
    LiveLife likes this.
  18. GeoDudeFlorida

    GeoDudeFlorida Member

    Joined:
    Dec 1, 2020
    Messages:
    3,874
    Sorry I responded to the wrong post. That was for @LiveLife re: his next myth busting episode. That’s what I get for trying to multitask.
     
  19. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    No problemo.
     
  20. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    What’s the source of this data? Anyone? Buehler?
     
  21. gunzby

    gunzby Member

    Joined:
    Nov 29, 2020
    Messages:
    53
    They weren't crimped as I do remember that. Maybe I'll run across one this week when I load a batch. If I do, I'll measure it.
     
  22. Ray P

    Ray P Member

    Joined:
    Jun 2, 2004
    Messages:
    448
    Location:
    NM
    Well that was a fun rabbit hole.

    In the product Q&A Brownells gives the primer flash hole reamer diameter for small rifle primers as 0.0625" and large rifle primers as 0.081".
    https://www.brownells.com/reloading/case-preparation/flash-hole-deburring-tools/sinclair-flashhole-reamers-prod36020.aspx?psize=48&msclkid=a9b6b4c174481bd02981d591e0dca016

    An article in accurate shooter cites the Norma & Lapua flash holes as "The standard dimension for Lapua 220 Russian and 6mmBR flash holes is 1.5mm or .0590″."
    http://bulletin.accurateshooter.com/tag/flash-hole/

    I'm surprised flash hole data seems to be the only measurement not provided in SAAMI/ANSI Z299.4 (centerfire pistol & revolver ammo) or 299.5 (centerfire rifle). But there is an Army Lab report on the effect of a smaller "spit-hole" (flash hole) on M80 7.62 NATO ammunition. Mil-spec flash hole diameter is given as 0.078". Good info on overall effect of smaller hole.
    https://apps.dtic.mil/dtic/tr/fulltext/u2/a599210.pdf
     
  23. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    Thanks

    Since this thread was originally about 9mm (and maybe 45acp) cases, some of this isn’t germane WRT sizing but thanks much regardless.

    I don’t know that I’ve ever seen a Norma 9mm pistol case so I’m not sure that’s germane either.

    But you’re correct it is interesting regardless.
     
  24. Ray P

    Ray P Member

    Joined:
    Jun 2, 2004
    Messages:
    448
    Location:
    NM
    What I found interesting is that the SAAMI spec for centerfire pistol cartridges was absolutely silent on the subject. It's been a few years since I've had free (paid for by someone else) access to a mil-spec archive, so I can't check the mil spec flash hole diameter for 45 Auto or 9 NATO. But that is where I would go next.
     
    GeoDudeFlorida and CQB45ACP like this.
  25. CQB45ACP

    CQB45ACP Member

    Joined:
    Nov 10, 2020
    Messages:
    1,141
    Location:
    Northern Virginia at the Beltway
    Yeah don’t know that’s in the cards…all I was after was some validation of the statements and assertions earlier in this thread that deburring flash holes and/or drilling out small ones to some random larger size would improve something, heck anything. I’m talking about actual validation. Proof. Seems there is no such proof.

    But in the accurate shooter link you provided (thank you again) there is an article from the Army marksmanship team about flash holes.

    Much interesting information on the subject (everyone here should read it) and one comment said it all…to paraphrase, if the shooter thinks it helps, it helps.

    Now I want an RCBS case prep station.
     
    Last edited: Sep 27, 2021
    Ray P likes this.
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice