High B.C. advantage?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by openlake, Jul 9, 2002.

  1. openlake

    openlake Well-Known Member

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    Jun 7, 2002
    I am new to LRH, so forgive me if I ask an obvious question. I have been playing with a ballistic program, (.280 Ackley Improved), and in general the higher b.c. bullets seem to start to shine at better than 800 yards. My question is, if I was shooting at 400/500 yards, does the higher B.C. and usually heavier bullet, offer any advantages to offset the usually slower starting velocity (than a lighter bullet)? [​IMG]

    I am beginning the process of building a rifle in .280 A.I., and am debating a 1/9 twist to aid the stabilization of the heavier bullets (160 grain) versus the 140 grain with a 1/10 twist. This rifle is not a true 1000 yard competetion gun, but a lighter mobile toten' gun designed for shots out to 500 yards. [​IMG]

    Sorry for the confusing wording. [​IMG]
     
  2. Jon A

    Jon A Well-Known Member

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    Yes. I'm guessing you're only looking at trajectory. If using a rangefinder, etc, you can correct for the trajectory disadvantage of the heavier bullets at those ranges rather easily.

    Now look at wind drift--the heavier, higher BC bullet will be better from the muzzle on out. Wind is much harder to correct for than drop. Less wind drift means better accuracy unless you happen to be shooting under really "perfect" conditions.

    And after the hit, look at retained energy. Using similar types of bullets, you'll find the 160's will hit much harder than the 140's. The farther the distance, the bigger the advantage.
     

  3. Guest

    Guest Guest

    Go with the 1:9" twist regardless... The 140's will shoot fine in that twist, if you want to use them, and you will also have the option of going to a heavier bullet, If you decide. I shot 140 Nosler BT's in my .280 Ackley for 3 years before going to the 162 gr. AMAX. The 162 found a sweet spot at 2880 fps MV and shoots one hole groups at 100 yds, and also does very well out to 1000 yds... Good luck--CJ
     
  4. openlake

    openlake Well-Known Member

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    Thanks guys, you have given me some good points to consider. Right now I am leaning towards a Krieger in 26", with a 1/9 twist with maybe the 150 grain ballistic tip.

    Chris, have you shot any game up close (<200 yds.) with the A-Max? And what powder are you using with the one holer load?
     
  5. Guest

    Guest Guest

    Sorry, nothing up close. Just some crows and a coyote at 800-950 yds.Really just found the load that it likes. 58.0gr of R22 gives about 2880 fps. I tried N560 but the velocity just wasn't there. Good luck with your loading... CJ