Barrel length and twist question

Discussion in 'Long Range Hunting & Shooting' started by Rainy, Apr 15, 2019.


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  1. Randy Tidwell

    Randy Tidwell Well-Known Member

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    Feenix, I agree with you, any change will affect performance.

    I just content the biggest factor is bullet lenght, not weight.

    JMHO
     
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  2. FEENIX

    FEENIX Well-Known Member

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    Sorry but you're still missing the point (but you're getting there :cool:), it is all 4. Going back to your .308 cal round nose, spitzer, VLD analogy, even if the bullet manufacturers managed to keep them all the same weight and length, because they have different designs, they'll have different BCs.
     
    Last edited: Apr 19, 2019
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  3. Randy Tidwell

    Randy Tidwell Well-Known Member

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    No, I get it completely. All aspects of the bullet design have a bearing on its inflight stability. I just contend the length of the projectile has more to do with its stability than weight or shape.

    JMHO
     
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  4. FEENIX

    FEENIX Well-Known Member

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    You at least progressively got better from your original post in #25.
     
    Last edited: Apr 19, 2019
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  5. Gerard Schultz

    Gerard Schultz Well-Known Member

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    That is why we ask questions on forums and read what others have to say. It might seem like the OP is being hi-jacked, but it is usually just an extension of the discussion/education.

    If a bullet is stable, the barrel will stabilize any bullet that is shorter (lighter), providing it is similarly shaped. Saying that it may not stabilize lighter bullets goes to another factor called tractability and generally becomes important with a 30 cal and shorter bullets at 500 plus.

    A 1:10" twist will allow the average 150gr jacketed bullet to be used up to about 600 yards. At longer distances than that, best is to switch to a heavier bullet. A 1 in 9" will allow a 150gr to be used at the same distance of about 600 yards or less, it will not hurt anything, but even longer bullets than 180gr (higher BC) can be used and will have the correct terminal ballistics.

    Actually one should measure twist in calibers. For instance a 1:10" twist .30 cal (twist = 32.5 cal.) is tighter than a 1:9" twist .243 cal (twist = 37 cal.)
     
    Last edited: Apr 20, 2019
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  6. LVJ76

    LVJ76 Well-Known Member

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    Definitely better explained than me, Lol. Well put.
     
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  7. Gerard Schultz

    Gerard Schultz Well-Known Member

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    The last sentence of my post above was edited after I reread it this morning. I cannot believe I made such a fundamental mistake, the lateness of the hour must have gotten to me :D
     
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