Berger, Sierra or Jlk

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by nddodd, Feb 22, 2011.

  1. nddodd

    nddodd Well-Known Member

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    Which one of theses three in .284 180 gr match bullets are the closest to their advertised bc's. I think the bergers are .659 sierras are .660 and the jlk's are .735. I read somewhere that the jlk's are exaggerated I was curious if anyone here could confirm these numbers.


    Thanks
    Nathan
     
  2. BryanLitz

    BryanLitz <b>Official LRH Sponsor</b>

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    Nathen,

    The Berger and JLK are very close to each other. Their shapes are the same, they're even made on the same jackets (JLK's are made on the same jackets as Berger's Hunting bullets, not Berger's Target bullets which have thicker jackets). .659 for a G1 BC is much closer for these shapes than .7+. G7 BC is .337. See this article for drawings of both bullets and analysis:
    Bryan Litz — Marksman, Rocket Scientist, Ballistics Guru « Daily Bulletin

    The new Sierra is a different cat. I haven't measured or tested these yet, but I have looked at them beside the VLD's. The nose on this new bullet is much shorter than any other 180 grain 7mm bullet, which will be bad for BC. I'm highly skeptical that the .660 BC is accurate for that bullet.

    Not picking on Sierra here. Sierra's banded BC's tend to be very good for most bullets, however they've had problems with 7mm. For example, they list .489 (average) for the 7mm 168 MK, and I measured .565 (14% higher) for that bullet. Also the 7mm 175 SMK they list (average) as .595 and I measured .637 (7% higher). But this new bullet, they seem to have overshot. Just looking at it next to a VLD of the same caliber and weight, anyone can tell it's a higher drag shape.

    One good thing about the short nose is that it might be the only 7mm 180 grain bullet that's mag length feed-able.

    SMK jackets are not designed for terminal performance on game though.

    -Bryan
     

  3. nddodd

    nddodd Well-Known Member

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    Thanks Bryan I figured the Jlk would be to good to be true. As for the Sierra bullet maybe someone will be able to test them soon. I've 500 of each and they both shoot really good in my guns. I just was curious how far off the published bc's were, I didn't want to run a ballistics chart for .735 or .660 and they be way bellow.


    Thanks again,
    Nathan