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1:7 Twist, preferable grain weight

Discussion in 'Black Rifle Forum' started by HomeLandPatriot, Jan 12, 2010.

  1. HomeLandPatriot

    HomeLandPatriot

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    For a 1:7 Twist bbl, what weight grain bullet should be used for optimal performance.

    1:7 twist typically requires a heavier bullet correct? 62gr or more?
     
  2. crazymoose

    crazymoose Nonentity

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    55 grain and over will work fine, although many say accuracy at range isn't as good with the 55 grain/ 1:7 combination. Unless you're shooting for tiny groups at 200+ yards, the difference is probably not noticeable. If you are shooting for tight groups at 200+, 55 gr. ammo is a poor choice anyway.
     

  3. HogGlocker

    HogGlocker Owner Since 88'

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  4. Jim Watson

    Jim Watson

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    Performance at what?

    A 7 twist doesn't REQUIRE a heavy (long) bullet but will stabilize them. It will shoot the 55 gr FMJ pretty well for casual use or urban shtf.

    A 7 twist will stabilize a 90 grain SMK but those have to be loaded over magazine length and fired single shot for long range target shooting.
    The heaviest bullet I know of to be loaded to magazine length is the 77 grain, which finds some military use in the Mk 262 round.
     
  5. RMTactical

    RMTactical Battle Born CLM

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    It doesn't "require" a heavier bullet but it is made as a compromise between the M855 and the M856. I would say that 68-77gr is the "optimal" grain for the 1/7 (in general).

    That said, 55gr works great too.
     
  6. HomeLandPatriot

    HomeLandPatriot

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    Thanks RM,

    thats exact kind of response I was looking for.
     
  7. KalashniKEV

    KalashniKEV

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    Exactly what I was going to post... "Optimal" is the word to use when discussing weight/twist.
     
  8. Kentak

    Kentak

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    My understanding is: 55gr = okay; heavier than that = better/best
     
  9. Alaskapopo

    Alaskapopo NRA ENDOWMENT

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    It does not require a heavy bullet but heavy bullets require a 1/7 or a 1/8 twist. I shoot 77 grain bullets in my 1/7 and 1/8 guns for matches and accuracy work. I use 55 grain ball for plinking.
    Pat
     
  10. Molon

    Molon

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    Quality 55 grain bullets will do much better than “OK” in fast twist barrels. People try to compare garbage FMJ 55 grain loads to heavy OTM loads and then make the ridiculous claim that 55 grain loads are not as accurate as 75-77 grain loads. Quality 55 grain loads can shoot superbly from fast twist barrels. The 10-shot group pictured below was fired from 100 yards from a Noveske barreled AR-15 with a 1:7” twist using 55 grain Sierra BlitzKings.

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    The next 10-shot group was fired from a Krieger barreled AR-15 with a 1:7.7&#8221; twist also using 55 grain BlitzKings.

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    Last edited: Jan 14, 2010
  11. gdvan01

    gdvan01

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