OVERSPIN ??? twist and bullet spin

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by denobravo, Jan 17, 2014.

  1. denobravo

    denobravo Member

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    well folks ...Im looking at a 300win mag with a 26 inch 1- 8 twist barrel
    Point being or question Im asking...Will a a bullet spin apart if its over spun...???

    All the berger recommendations are at least a 1 in 11
    so....Im skeptical....do bullets actually fly apart from over spinning ??
    I cannot conceive of a manufacturer selling a rifle that wouldn't shoot bullets...sounds weird but I want OUTSIDE input

    thanks folks
    denobravo
     
  2. Broz

    Broz Well-Known Member

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    Tighter twist when added to velocity can and will produce damage to jacketed bullets.

    I believe that the only thing to make this worse if to do it with a 3 or 4 grove barrel instead of 5 or 6.

    A 1 in 10 twist barrel will stabilize even the biggest Bergers (230's) The 1 in 10 is definitely all one needs for a 300 win.

    I can not imagine why anyone would offer or want a 1 in 8 win a 300 win. Are you sure the rifle you are looking at is a 1 in 8?? I find that strange.

    Jeff
     
  3. elkaholic

    elkaholic Well-Known Member

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    I agree with Jeff! There is nothing to be gained from over twisting and potentially, much to lose. Twist requirements are more directly connected to length than weight. The idea is to use just enough twist to stablize the longest bullet that you will be shooting, taking into consideration the elevation you will be shooting it at. If bullets were perfect in balance and concentricity, it wouldn't be as much of an issue, but of course they aren't. Also, as Jeff mentioned, wider lands are harder on bullets and accentuate the problems of higher rotation. Except for some of the extremely long 250-260 grain tipped bullets that I have played with, I can't think of an occasion where an 8 twist would be needed in a .308"....Rich
     
  4. Jud96

    Jud96 Well-Known Member

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    I agree with Broz and elkaholic. I don't know what you'd do with a 1-8 in a .300 Win! I don't think you'd need an 8 for even a 240gr SMK.
     
  5. denobravo

    denobravo Member

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    thanks guys...Nemo Arms ...Kalispell MT...military AR platform..1500 yrd military weapon...look em up...Im waiting for a return phone call
     
  6. 300whisper

    300whisper Well-Known Member

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    What else does over spin cause (accuracy wise)? Can't the spin actually move the bullet off target or is that only ELR? I always thought over stabilization can cause the bullet to tumble.
     
  7. Jud96

    Jud96 Well-Known Member

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    Well it can cause instability which leads to innaccuracy.
     
  8. elkaholic

    elkaholic Well-Known Member

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    It is true that more twist/spin will cause a bullet to drift more at distance but that can be compensated for. The problem with spin/twist that is more than necessary is it makes any imperfections in the bullet show up. I guess you could think of it as wheel on a vehicle being out of balance. You may not notice it at lower speeds but it increases with speed.....Rich
     
  9. MontanaRifleman

    MontanaRifleman Well-Known Member

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    "Over spin" or "over stabilization" is a relative term. It all depends on your application. In the world of dangerous game and brush hunting, the more spin the better.

    There is no such thing as over spin or stabilization at short to mid ranges. The only possible draw backs are if you are using thin jacketed bullets and pushing then at high velocities where they migh deform or come apart as mentioned.

    In long range shooting, the draw back to more stabilization than needed is the bullet will not nose over after it passes the apex of its trajectory.

    another draw back to more tweist than you need is reduced velocity. Not a big deal, but you will loose a little velocity with a tighter twist.

    That said, I would not buy a 30 cal barrel with an 8" twist unless I was shooting long monometal type bullets requiring that much twist. There are no 30 cal lead core bullets that I know of which require tighter than a 10" twis
     
  10. elkaholic

    elkaholic Well-Known Member

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    I would mildy disagree with the "no such thing as overspin at short to mid ranges" as overspin does affect accuracy to a degree. Any imperfections in the bullet will be accentuated and cause a loss of accuracy. It may not be much, but a mid range at least, it could be significant
     
  11. MontanaRifleman

    MontanaRifleman Well-Known Member

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    I don't know enough about that to disagree with you Rich... so I'll take your word for it :)
     
  12. Bravo 4

    Bravo 4 Well-Known Member

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    Sounds more like the twist for a 300 whisper or Blackout shooting subsonic.
     
  13. 300whisper

    300whisper Well-Known Member

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    Excellent point 4 Bravo. That's the only time I've seen a 1:8 on a 30 cal.
     
  14. elkaholic

    elkaholic Well-Known Member

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    DARN! I was hoping for a good pee'in match!:D