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Thread: Speer 75gr Gold Dolt Twist Rate

  1. #1

    Speer 75gr Gold Dolt Twist Rate

    Will this load stabilize in a 1:9 or does it need a 1:7/8?

  2. #2
    What is the barrel length? The longer the barrel is and the higher the velocity is, the more you can get away with on slow twists.

    Just the same, a 7 would be preferred, with 8 being borderline acceptable in my opinion.

  3. #3
    It shoots ok in a 1/8 twist RRA NM barrel I have... pretty well in fact, 1-1.5 MOA if I do my part.

  4. #4
    18in. Barrel seems to shoot fast. My Win 55gr FMJ stays around 3150fps (Spec is 3270 from a 24in) so I'd imagine this load would run around 2600ish.

  5. #5
    Quote Originally Posted by WDR View Post
    It shoots ok in a 1/8 twist RRA NM barrel I have... pretty well in fact, 1-1.5 MOA if I do my part.
    Makes me think a 1:9 will be too slow. Thanks.

  6. #6
    Site Supporter DocGKR's Avatar
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    1/7 would be better for a variety of reasons.
    Facts matter...Feelings Can Lie

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    Quote Originally Posted by DocGKR View Post
    1/7 would be better for a variety of reasons.
    +1

    I have had VERY good results using 1/7 with this round, but also never owned anything but 1/7, because I see no need for 1/7+ twists in the 5.56 AR platform. They are limiting, and pointless.

  8. #8
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    Quote Originally Posted by Unobtanium View Post
    +1

    I have had VERY good results using 1/7 with this round, but also never owned anything but 1/7, because I see no need for 1/7+ twists in the 5.56 AR platform. They are limiting, and pointless.
    Actually, up to 1/9 is very useful, it just usually comes in substandard quality guns. The 1/7 twist was adopted solely because some wonks thought it would be a great idea to have the capability to shoot M856 tracer in the gun. 1/9 will stabilize the M855 load, but not its companion tracer round, so along came the 1/7. BTW, it was never intended for M855 (Green Tip) to be a standard service round for the M16/M4, but only in the M249 SAW. Since we've trended much heavier in projectiles for the caliber, I guess it turned out ok.
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  9. #9
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    Quote Originally Posted by Wayne Dobbs View Post
    Actually, up to 1/9 is very useful, it just usually comes in substandard quality guns. The 1/7 twist was adopted solely because some wonks thought it would be a great idea to have the capability to shoot M856 tracer in the gun. 1/9 will stabilize the M855 load, but not its companion tracer round, so along came the 1/7. BTW, it was never intended for M855 (Green Tip) to be a standard service round for the M16/M4, but only in the M249 SAW. Since we've trended much heavier in projectiles for the caliber, I guess it turned out ok.
    1/7 also shoots 40gr very well. I lose nothing. 1/9 does. No use for it. I am familiar with the history thereof, and how it came to be, and why, and so forth, and my M856 was created.

  10. #10
    Site Supporter DocGKR's Avatar
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    Faster twists have some significant external and terminal ballistic advantages as a result of faster rotational velocity--this is especially important with both shorter barrels and longer ranges. Of course the projectile must be robust enough to handle the increased forces without coming apart in flight...
    Last edited by DocGKR; 10-09-2018 at 08:59 AM.
    Facts matter...Feelings Can Lie

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