Do JLK Bullets Really have a BC that is So Much Higher than Berger ?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by 300magman, Jul 7, 2011.

  1. 300magman

    300magman Well-Known Member

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    Just like the title says, are JLK bullets really so superior to Bergers when it comes to BC. If so, is there some downside, because I hear about Bergers being used everywhere and hardly hear a word about JLKs

    Claimed JLK BC
    7mm 168gr = 0.690
    7mm 180gr = 0.735

    Claimed Berger BC
    7mm 168gr = 0.617
    7mm 180gr = 0.659

    BTW, I'm thinking about using them in F-Class, not hunting.
     

  2. ICANHITHIMMAN

    ICANHITHIMMAN Well-Known Member

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    If you do a search you might find some of the awnsers to your questions. We have discused it before with the help of JLKs owner and Eric from Berger. The short awnser is yes just a bit higher than the Bergers and for all intense and purpose the same bullet.

    Jon
     

  3. Mikecr

    Mikecr Well-Known Member

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    I believe it's how BC is currently reported by Berger.
    They've normalized their G1BCs to provide an average from muzzle to target.
    For most it accounts for the variance of G1BCs as velocities change in flight.

    JLK BCs are still based on some muzzle velocity, like all other bullet makers.

    This can benefit or hurt you, depending on your ballistic software.
    Most software does not adjust BC incrementally with each incremental velocity downrange. This is in a sense a circular loop, in that BC affects downrange velocity, which affects BC!
    But this is possible, and so probable somewhere out there.

    Berger normalized expected velocities with their bullets, and assigned BC based on that velocity, to reduce software prediction error across a gamut of ranges.
    It's a good move.
    Bergers and JLKs are actually pretty close, but I think Berger's BC numbers are more useful.
     
  4. 300magman

    300magman Well-Known Member

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    Thank you for that explaination, that is about as well as I have ever heard it put.

    I had seen a few others posts on this topic but I didn't really get a sence of resolution from them. Some seemed to think JLK's number were spot on, while others pointed out that they couldn't be much, if any, different from Berger's because they were too close to identical.
    Your explaination really rationalizes both.
     
  5. Cauterucio Bullets

    Cauterucio Bullets Member

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    According to Bryan Litz's book my 7mm 177 & 189 gr VLD's are king of the BC's so I've been told. Several long range shooters have said that my 177gr has a 750 BC @
    2700 fps MV. I cannot say one way or the other, as I have no way of testing BC's.
    In my opinion I want them all to go into the same group. What has a shooter gained if the bullet has a high BC but does not group well.
     
    Last edited: Jul 9, 2011
  6. Rocky Mountain

    Rocky Mountain Well-Known Member

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    I've shot the cauterucio 176gr with great results and yes your so right a higher BC means nothing if the bullet dose not group the best and consistantly all the time.lightbulb
     
  7. trophyhunter170

    trophyhunter170 Active Member

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    Measured BC's for some bullets you mentioned, they are as follows. Note these are G1 BC's, all averaged from 3000 to 1500 fps which is they way Berger computes their bc's I believe. This info came from a man who performed the test and knows his stuff.
    Berger 180 VLD: .659-------------Length into lands is 2.847
    Berger 180 Hybrid: .674-------------Length into lands is
    JLK 180 VLD: .645-------------Length into lands is 2.875
    Cauterucio 177 VLD: .683-------------Length into lands is 2.840
    Cauterucio 189 VLD: .703
     
  8. Mikecr

    Mikecr Well-Known Member

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    Well there may or may not be a gain in it.
    BC ALWAYS matters though, even when you THINK it's not important.
    It's the very reason LR shooters use high weight for cal bullets(whether they know it or not).

    If GROUPING was all that mattered LR shooters would be shooting flat base, lower BC bullets in slower twists.
    When ACCURACY matters(as it does here, and with every single shot), LR shooters need to mitigate mis-hold errors with wind.
    That's not to suggest that BC should be the sole consideration, but that it should not be blown off either.
     
  9. RMulhern

    RMulhern Well-Known Member

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    All hype and BS galore! Just like the auto dealers who'll say anything in an attempt to get the gullible public to buy their product!:rolleyes: