G7 bc for .277 165 grain matrix vld

Discussion in 'Long Range Hunting & Shooting' started by Paramudd, Jan 20, 2012.

  1. Paramudd

    Paramudd Active Member

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    Can anyone tell me what the g7 ballistic coefficient is?
     
  2. ShanMan

    ShanMan Active Member

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    I just caught wind of those bullets too. Never knew they made a 175gr vld for the .270! I wonder how that will affect barrel life though... I am going to email the company and ask them if they have any of that information to send over.
     

  3. FEENIX

    FEENIX Well-Known Member

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  4. Joe King

    Joe King Well-Known Member

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    Not sure if Bryan has gotten around to this bullet yet, but the cacl G1 bc being 0.7381 it's close to their 168gr 7mm VLD which has a calc G1bc of 0.7136. I spose you could extrapolate and get pretty close (not exact) using the measure G7 bc of the 7mm 168gr which is 0.311 (berger 168gr VLD is 0.316) and apply <-- that to the 270 165gr. I figure it'll be in the neighbor hood of 0.315 - 0.325. Perfect? no. But I bet it would get you in the park :)
     
  5. FEENIX

    FEENIX Well-Known Member

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  6. MuleHunter

    MuleHunter Well-Known Member

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    Post number 24 was an estimate. I have tested the matrix 175 here is the info for my testing.

    G7=.3225

    G1=.6435

    My friend who has a similar test method as me has tested the 165 matrix at the following,

    G1=.638

    That would make the G7=.319

    Good luck, make sure your scope tracks when your figuring out your drop data, if the click values are off on your scope it will mess up your solutions from your ballistics program and you will be chasing velocity and BC numbers trying to get it to match.
     
  7. ShanMan

    ShanMan Active Member

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    Thanks for the advice and information I appreciate it.
     
  8. bigngreen

    bigngreen Well-Known Member

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    Mulehunters numbers are a dang good place to start IMO, depending on the program you use it will get you out there a ways. With the 165 I can use a G1 BC of .650 in Loadbase and it will be nuts on to 1890 yards, using Applied Ballistics program a G7 BC of .314 work very well this last weekend shooting 1001 and 1890 yards, a G1 needs to be stepped to get out there that far.
    Very fun shooting a 270 WSM that far, it holds it own rather well!! I just passed 800 rounds on this barrel and the throat is holding well!!
     
  9. FEENIX

    FEENIX Well-Known Member

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    I remember you providing the same above info but can't seem to find your post to the thread.
     
  10. bigngreen

    bigngreen Well-Known Member

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    It's in the ELR section.
     
  11. FEENIX

    FEENIX Well-Known Member

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    Copy that, thanks!
     
  12. FEENIX

    FEENIX Well-Known Member

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  13. Truc

    Truc Well-Known Member

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    I just bought a 270 STW w/ a 26" barrel used. It came w/ 150 rds of new brass getting 3450 fps w/ the 150 gr partition bullet so I'm hoping I will get 3300 fps w/ the 165 Matrix. That should smoke um
     
  14. MuleHunter

    MuleHunter Well-Known Member

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    bigngreen has played with the 165's allot more than I have. The .650 BC number intrigues me. I sought to mimic Litz's testing of providing an average BC across the 3,000 fps to 1,500 fps velocity band. Using a point mass solver like Shooter, JBM, or the G7 ballistic programs my numbers have been perfect. I think that is what bigngreen was trying to say in not so many words. Loadbase is not a point mass solver from what I understand, so if you are using a free online program start with my numbers. If you are using Loadbase use bigngreen's numbers.