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"Spoon" FMJ Bullet

Discussion in 'Caliber Corner' started by dkf, Jan 20, 2013.


  1. dkf

    dkf
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    An interesting yet simple way to try and promote bullet tumbling when it enters the target to try and increase energy transfer into target. Pretty interesting and looks effective.

    [ame]http://youtu.be/m3b5Qoxu1l4[/ame]
     

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    #1 dkf, Jan 20, 2013
    Last edited: Jan 20, 2013
  2. M 7

    M 7
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    The technology was also used for the HK MP7A1 4.6x30mm-

    http://world.guns.ru/smg/de/hk-mp7-pdw-e.html

    I think it is a very innovative way to increase terminal ballistic performance.

    Looks like John Ervin (of Brassfetcher.com fame) ground a small, off-center flat onto the nose of the FMJ- very easy to do with a file although I am not sure that I'd wanna do that for ammo that I'd be using for self-defense.

    Cool vid.

    Thanks, dkf.
     

    #2 M 7, Jan 20, 2013
    Last edited: Feb 7, 2013
  3. Glock19Fan

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    For some reason I couldnt view the video, but here are a few of my thoughts.

    1. I wonder how much quicker the yaws compared to an FMJ with an air pocket.

    2. I wonder if there would be any feed issues?

    3. It would seem that a bullet of this design wouldnt do very well against bone. I would think it would be easily deflected.

    4. If the yaw and change in direction was too significant, then would could completely miss what you were aiming for. I would hate for a bullet through the sternum to change direction and penetrate the intestines.
     
  4. uz2bUSMC

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    My thoughts on this..

    What do you mean air pocket? More specifically, where do you mean that air poscket to be located? An air pocket in the rear of the bullet would most likely fight yaw since the bullet would most likely be frontal weight biased.

    Deflection would probably be minimal on bone compared to standard pistol fmj profile.

    Yaw is what makes a good percentage of FMJ rifle rounds perform (as you probably know). Yaw being the portion of movement beginning a tumble doesn't mean the bullet will take the path of a rainbow. The bullet has a desire to travel forward on it's original path based on it's momentum. Although it can and will deviate based on it's profile, it's tendancy to stay on course should be stronger than it's ability to radically deviate because of retarding forces.
     
  5. dkf

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    Looked to me like the yawing started a little after the first 1/3rd of the gel.

    I doubt feeding will be affected. The "spoon" is fairly small and not sharp.

    Due to the length vs diameter of most pistol bullets and the fairly low velocities a pistol bullet sees vs rifle I would guess the bullet path does not wander that much.

    I think it is possible a yawing fmj would probably work just as good as a JHP against bone. Especially if the jfp expands prior to hiting the bone and/or fragments. You can usually count on an FMJ not coming apart at pistol velocities. This test was a "mouse gun" caliber so larger calibers may act differently.
     
    #5 dkf, Jan 20, 2013
    Last edited: Jan 20, 2013
  6. Glock19Fan

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    Many foriegn rifle calibers have an air pocket at the tip of the bullet to shift the center of gravity to the rear, encouraging an early yaw.

    As I mentioned I wasnt able to view it but now that I see it, I take back my original statement about over yawing with pistol calibers, but with a rifle caliber, and early yaw would mean more bend in the bullet (assuming it doesnt fragment). Long, bent projectiles tend to have erratic flight paths and would result in a senario I mentioned in my previous post.

    Overall I think it would be a good idea. As long as the spoon was smoothed over to avoid feeding problems, and accuracy wasnt effected too much it would be a good option for people that cant use expanding projectiles.
     
  7. uz2bUSMC

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    Gotcha:thumbsup:
     
  8. Tiro Fijo

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    Yes, but this was not intentional. It happened as a result of the manufacturing process whereas when the steel jacket was formed around a lead core a minute air gap was formed between the top of the lead core & the jacket. The most famous case being the Russian 5.45 x 39mm round.
     
  9. Glock19Fan

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    It may have been accidently discovered, but it is an intentional process now.
     
  10. fredj338

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    IT seems acccuracy past contact distances would suck, maybe not. The simplest way to get better perfromance form any FMJ is to flatten the meplate & add a very shallow cup, really a saucer, concave dimple. It's been done for a few years in large caliber big game bullets.
    I tested some myself, solid bronze Barnes w/ a very shallow cup point turned inot the nose. Penetration is not affected, as in a tumbling bullet, & it seems to set up a cavitation in front of the bullet as it passes thru tissue. I only had wetpack to tet mine, but hunters in Africa give high marks to a sim bullet made there. It could easily be adopted for military use in the 9mm. I doubt much could be done w/ the 223, but maybe.
     
    #10 fredj338, Jan 21, 2013
    Last edited: Jan 21, 2013
  11. Tiro Fijo

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    Source?
     
  12. Glock19Fan

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    The same manufacturers produce other calibers lacking the air pocket.

    If you realized a mistake in your manufacturing method produced a better performing bullet, would you change it for the worse?

    Whether or not it is documented, it is apparent the same method is used today for the advantage of better terminal performance. Or at least that is my train of thought.
     
  13. SCmasterblaster

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    I have never heard of such a thing.