Pointing Berger 105 Hunting and Hybrid bullets

Discussion in 'ELR, Ballistics & Bullets Board' started by SteveOak, May 12, 2018.

  1. SteveOak

    SteveOak Silver $$ Contributor

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    Are Berger 6mm 105gr VLD Hunting and Hybrid Target bullets candidates for meplat trimming and pointing?
     
  2. Keith Glasscock

    Keith Glasscock True believer - Straight 284 Gold $$ Contributor

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    Steve,

    I tested 105 hunting VLD's pointed vs unpointed at 1000 yards back in 2015. 10 shots each at Phoenix. I was unable to see any change in vertical point of impact. As a result, I no longer point that bullet.

    Other bullets have responded affirmatively to pointing (7mm 180 hybrid, 30 cal 200 hybrid) by showing repeatable differences in vertical group center.

    YMMV,
    Keith
     
  3. SteveOak

    SteveOak Silver $$ Contributor

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    Hello Keith,

    I hope that you are well.

    Thanks for the reply.

    Not the answer I was hoping for but very helpful nevertheless. It is what it is.

    Some days I love this site!!!

    Best regards,

    Steve
     
  4. Ballisticboy

    Ballisticboy

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    For a fixed nose length it has been proven that adding some degree of blunting can reduce the drag of the nose with the right shape for the blunting. As the amount of blunting is increased the drag will continue to reduce until an optimum value is obtained and then the drag will start to increase with increasing bluntness.
    Thus if the bullet you are using has less blunting than the optimum value then changing the nose shape to a point with the same nose length will increase the drag, not decrease it. If the blunting is too large to start with, reducing the blunting will reduce the drag until the amount of blunting is reduced beyond the optimum in which case the drag will start to increase again.
    The optimum amount of blunting will vary depending on the shape of the blunting and the speed of the bullet. Around 10% is a reasonable value to start with but remember it depends on the shape of the blunting and the bullet.
     
  5. SteveOak

    SteveOak Silver $$ Contributor

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    I don't understand what you mean by blunting a bullet.
     
  6. damoncali

    damoncali Gold $$ Contributor

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    He means a meplat as opposed to a sharp point. Data shows that a sharp point is sub optimal from a drag point of view, and that roughly speaking, a .10 to .15 caliber flat on the nose will reduce drag. So if you point too much, you can increase drag (just as if you have too large a meplat diameter). You really don't want to bring a .308 meplat under 30 to 40 thous in diameter, for example. The exact optimal meplat diameter is hard to pin down. That's the theory at least, which is backed up by a good deal of testing by the BRL back in the day.

    A relatively straightforward summary can be found here: https://catalog.hathitrust.org/Record/101827360
     
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  7. 6BRinNZ

    6BRinNZ

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    This is interesting. The high bc monolithic bullets come out with what looks like needle tip meplats.
     
  8. DocBII

    DocBII

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    SteveOak,

    Works on Hybrids. Never tested on hunting.

    DocBII
     
  9. SteveOak

    SteveOak Silver $$ Contributor

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    Hmm, the Berger 105 hybrids, according to the Berger website, require a 7 twist, my barrel is an 8. However, I don't have a problem with 115 DTACs and I know people that shoot the Berger 115 hunting bullet in an 8 twist so I may have to give them a try.
     
  10. DocBII

    DocBII

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    SteveOak,

    8 twist in both of my match .243s. YMMV.

    DocB
     
  11. Laurie

    Laurie

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    So ....... those CNC machined bullets with needle tips that can penetrate skin that turn up every now and then from people who aren't experienced bullet-makers actually have ballistically sub-optimal tips! Who'd have thought it? :)
     
  12. damoncali

    damoncali Gold $$ Contributor

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    That’s what the old tests and theory would say. I’m surprised I haven’t seen someone trim them down and test them.
     
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  13. Ballisticboy

    Ballisticboy

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    Perhaps I should clarify a little what has been said. If you take a pointed bullet with no meplat and just take the point off it you will increase the drag. However, if you keep the same nose length and have a nose with a small amount of meplat then you will reduce the drag slightly compared to the pointed bullet.
    This works because to the airflow the nose with a small meplat is effectively longer than the pointed nose and thus lower in drag.
     
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  14. damoncali

    damoncali Gold $$ Contributor

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    Good point. Trimming would change the nose length. Still though, it seems like they ought to machine them with a meplat, no?
     
  15. Ballisticboy

    Ballisticboy

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    If they made a nose of the same length with a hemispherical shaped meplat of around 10% of the bullet diameter then yes they should get a lower overall drag.
     
  16. Clearlight

    Clearlight

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    Don’t point Bergers hunting bullets , for use on live targets I’d leave
    them as is for best expansion .

    Was spotting for a friend at 1250 yards the other day , using pointed
    AR 130 Hybrids in a 6.5. 47 , and it was difficult to spot the occasional
    miss . His Bergers were also moly coated . We both had no problem
    spotting my misses ( 10 inch steel plate ) using the same bullet ,
    similar velocity , straight out of the box : the usual small clump of dirt
    and grass displacement was easy to see . Ground was damp and grass
    was about 3 inches high .

    We were both surprised at what we were seeing , the pointed and
    coated bullets seemed to just drill into the ground with very little
    signature .
     
  17. dkhunt14

    dkhunt14

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    To find that out, shoot pointed against non pointed at 1000 yards. Color 5 red and 5 blue and shoot them in a string. It will clearly show if there is a change. Some make a lot of elevation change and some bullets don't. Matt
     
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  18. Joe Salt

    Joe Salt Silver $$ Contributor

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    Wonder were you seen that before!

    Joe Salt
     
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