.243 win 1:8 twist (55gr-75Gr)

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by OneShot0351, Nov 26, 2012.

  1. OneShot0351

    OneShot0351 Well-Known Member

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    Dec 11, 2010
    anyone accurately shoot lighter varmint bullets,(55-75gr) in a .243 w/ 1:8 or faster twist barrel? thoughts,ideas,experiencing, load data . . .
     
  2. green 788

    green 788 Well-Known Member

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    Yes... out to about 300 yards. Beyond that, you'll have trouble.

    caveat: you'll hear from folks who shoot golf balls at 600 yards with 55's in their .243 fast twist barrels. It's up to you if you want to believe that. ;)

    Okay...

    The problem with spinning bullets too fast is that they'll resist the axial change necessary to fly tip first at the midrange trajectory point. Ballisticians can fret things out on paper, but the only paper that really counts is the target. At long range, the short, low BC bullets will begin to spread out due to the fact that they resist the axial change when they cross the "top of the rainbow" and they end up descending--for a time--like the space shuttle: belly up... (some folks mistakenly teach that bullets descend this way anyway, but of course have a hard time explaining perfectly round holes on targets at extreme ranges, so don't get led out into the weeds)...

    That belly up descent imparts a yaw (wobble), and the bullets begin to deviate from the path they should be on. Yes, they will eventually slow down and begin flying tip first, but not by the time they've deviated considerably from where you want them to be.

    Compare the 400 to 600 yard targets shot by .243 Winchester's pushing 55's (9 twists) to targets shot by 22-250's with 12 twist shooting the .22 caliber 55's.

    So... if you're not going long with these bullets, you can make them work. But for ranges past 300 to 350 yards max, it's going to be better to put a longer, higher BC bullet in that 8 twist.

    Dan
     

  3. OneShot0351

    OneShot0351 Well-Known Member

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    Thanks Dan, that's all i'm looking for is 400 MAX, just something to point and shoot, no dial, for coyotes and bobcats, just wanted to make sure i wasn't gonna have any stabilization or tumbling issues right off the bat working with such a light bullet and be pursuing a lost cause. shooting the 105 A-MAX @3080 right now at deer is working great, but in that close of range for a much smaller target, moving your drop 3-4in less @ 300 and 5-6 in less @ 400 help when having to make a fast shot.