.1 grain of powder make a difference?

Discussion in 'Reloading' started by YamaLink, Apr 1, 2010.

  1. YamaLink

    YamaLink

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    Setup: G34. Totally stock except for Warren sights and polish job on internals.

    WSF at 4.8 and 4.9 and 5.0 batches
    Federal primer
    OAL is 1.130 give or take
    MG 124 fmj

    So I'm sampling a bunch of the above and the 4.9 and 4.8 seem the same. Casings anywhere from 1 to 3 feet away. The 5.0 is about 2 to 5 feet. One FTE with the 4.9 (one-handed drills), accuracy is my typical newbie G34 self which means low/left due to poor trigger control or pretty darn spot on which means I actually took the time to get a sight picture and work that nice trigger at distances up to 15 yards.

    From a competition shooting perspective is it going to matter at any distance having a 4.8 or 4.9 or 5.0 (I stopped at 5.0 because above that I could tell a diff in recoil and time back on target).

    Question: Would you go with the highest powder charge for distances up to 25 yards? My sights are set for 6 o'clock hold if that matters. Or would you go with the lowest recoiling?

    I've only shot up to 15 yards due to bad weather. Until I can march off 25 yards and practice targets....thought I'd ask here.
     
    Last edited: Apr 1, 2010
  2. CTSixshot

    CTSixshot

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    My older "Winchester Reloader's Manual" lists 4.7 to 5.3 for WSF with the 124g FMJ. It looks as if you should meet Power Factor of 125 for any of these loads, if that is even a necessity. You'll have to see if the 1 or 2 tenths grain makes any difference in point of impact and decide accordingly. As long as they all function and shoot well for you, I won't notice a tenth grain from my house.
     

  3. PCJim

    PCJim Senior Member

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    You're asking two questions if I read your post correctly...

    I would have to say, no. A difference of 0.1gr of powder at those charges will not be noticable up to 25 yards if shooting without a bench rest.

    I would use the charge that feels most comfortable and allows your quickest sight reacquisition. Again, unless you are benchrest shooting or measuring velocities over a chronograph, you probably will not notice any difference on the target.

    Now, if we were discussing a spread of 0.5gr powder charge from min to max, I would expect you to be able to tell a difference. And at 25 yards, it could probably be discernable on paper.
     
  4. IndyGunFreak

    IndyGunFreak

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    Well, eventually .1gr is gonna make a difference between blowing up and not blowing up... :)

    In your application though, it probably doesn't make that much of a difference. Just follow PCJim's advice for picking out what you want to use, and have fun.
     
  5. YamaLink

    YamaLink

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  6. MoNsTeR

    MoNsTeR

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    If those are traditional round nose FMJs I would bump the OAL to 1.169". But to answer your question, a tenth of a grain is not going to make much difference with a medium speed powder like WSF.
     
  7. YamaLink

    YamaLink

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    They are https://secure3.mooseweb.com/montanagoldbullet.com/images/320x200/9mm-FMJ-124.jpg

    34 OAL range seems to be all over even up to 1.16. Most seem to be at 1.13-ish depending on bullet specs.

    I just built some 4.8 rounds at 1.15 and see will see how things go. Probably should take some 5.0 at 1.15.

    Why would you go 1.169, the max?

     
    Last edited: Apr 1, 2010
  8. fredj338

    fredj338

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    I don't think 0.1gr diff in charge wt is noticeable on a target @ 25yds. it may shoot tighter groups or not, but should have no affect on POI.
     
  9. KB2MBC

    KB2MBC NRA Life Member

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    Gotta remember there is numeric rounding on a digital scale.
    On a digital scale that displays down to tenths, 4.9 grains can actually be a charge weighing in between 4.851 and 4.949, or simply +/- 0.05 grains.
     
    Last edited: Apr 1, 2010
  10. fredj338

    fredj338

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    Which would also mean nothing, exspecially w/ medium to slow burn rate powders.:dunno:
     
    Last edited: Apr 1, 2010
  11. BBJones

    BBJones

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    For my G17 I load to 1.14 OAL for both 115FMJ and 124FMJ. No real good reason for it, but has worked well and I don't see a reason to change it.
     
  12. YamaLink

    YamaLink

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    Wow, I owe a big thanks!

    Went back with 1.15 oal and 4.8 and 5.0 WSF; Montana Gold 124 fmj.

    The 1.15 was insanely more accurate, easier shooting, faster back on target, less recoil (not that the recoil of a 1.13/4.8 WSF is anything). Each round passed cleanly and ejected about 2 to 3 feet.

    This morning was the 1.130 at 4.8 WSF. Took a mag's worth of that along this evening. The OAL difference of going to 1.15 made my shooting seem almost effortless.
     
    Last edited: Apr 1, 2010
  13. KB2MBC

    KB2MBC NRA Life Member

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    Umm, yeah. Pretty much.
     
  14. shotgunred

    shotgunred local trouble maker

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    My current IDPA load is 4.7 WSF 1.1 OAL Rainier 125 FMJ.
    It makes power factor with a G17 and is plenty accurate.
     
  15. MoNsTeR

    MoNsTeR

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    Because it is the max (more case capacity = safer), and also because that is factory length and the length that 9mm guns have been built around since the Luger.
     
  16. DoctaGlockta

    DoctaGlockta

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    Yes .1 grains does make a difference over......

































    [​IMG]

    One million loads
     
    Last edited: Apr 2, 2010
  17. cyberiad

    cyberiad

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    I don't have any 9mm loaded that long but at 1.169 they may not fit in a Glock magazine.
     
  18. MoNsTeR

    MoNsTeR

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    Measure a round of Winchester factory 115gr FMJ, it will measure 1.170". If factory ammo didn't fit in Glock magazines I'd think we'd be hearing about it.
     
  19. cyberiad

    cyberiad

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    The last measurements I have are from some time ago:

    Fed AE 147gr TC 1.061
    Fed AE 115gr FMJ 1.151
    Fed AE 124gr FMJ 1.151
    Blazer Aluminum 115gr 1.115

    My notes are not complete but I think the last "white box" I had was around 1.146

    Maybe it's all changed now.
     
  20. CitizenOfDreams

    CitizenOfDreams

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    Here are some factory 9mm 115gr FMJ ammo measurements (10 rounds average)...

    Federal American Eagle 29.29mm/1.153"
    Precision Delta 29.37mm/1.156"
    Golden Bear 29.43mm/1.159"
    Wolf 29.50mm/1.161"
    Winchester 29.50mm/1.161"
    Sellier & Bellot 29.52mm/1.162"
     
    Last edited: Apr 11, 2010