Range Report JBM Update: Measured BCs added to bullet library

BryanLitz

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<span style="font-size: 14pt">On behalf of "JBM Small Arms Ballistics" and "Applied Ballistics, LLC" I would like to announce the addition of measured BC data to the JBM bullet library.</span>

For those who are not familiar with the free JBM online ballistics calculators, this is an excellent resource for making accurate trajectory predictions as well as calculations involving stability, recoil, max range, etc.

When calculating trajectories, users can either enter a numeric BC value manually, or select a bullet from the drop down menu. Until recently, the drop down menu would use the BC that's advertised by the manufacturer. Advertised BCs may or may not be accurate for any number of reasons. Now, the bullet library includes the BCs measured by Applied Ballistics, LLC (Bryan Litz) which are referenced to the G7 standard, and are accurate within +/- 1%.

Click here to read about G7 referenced BCs.

The bullets in the JBM library that use the measured BCs are designated "Litz", as shown in the following graphic. When you select these bullets, the program automatically loads the measured BC for that bullet. Just take care in entering all the other inputs accurately, and the program will output a very precise trajectory.

JBM_Lib.png


The numeric BC values of the bullets in the library are not visible to the user. If you want to know the numeric BC values, they're published in the book: " Applied Ballistics For Long Range Shooting " for over 175 long range bullets of all brands, from .22 thru .338 caliber.

Here are some links to the information on the JBM site which explains the new addition in greater detail:
Ballistic Coefficients
Bullet Library

This marriage of accurate data with accurate software will make it easier for shooters to calculate reliable trajectories. You no longer have to get the accurate BCs from one place, then go somewhere else to use them; it's all tied together now.

Take care,
-Bryan
 

spot69221

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Jul 12, 2008
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Re: JBM Update: Measured BCs added to bullet library

Sweet, someone should give you a foot rub for doing this!

P.S. not me though.
smile.gif


Thanks
 

trigger time

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Aug 16, 2006
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Re: JBM Update: Measured BCs added to bullet library

Thanks for all your work!
Now who do we have to get ahold of to get those 338 bullets out in our rifles? I got tired of calling and asking about them.
 

kombayotch

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Sep 20, 2007
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Re: JBM Update: Measured BCs added to bullet library

Great idea!
 

jasonk

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Feb 23, 2007
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Re: JBM Update: Measured BCs added to bullet library

Bryan....I noticed the 338 Berger bullets are listed, please pm me for my mailing address and send me some
laugh.gif


Seriously, any news on when they'll be available?
 

pvfd304

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Aug 29, 2006
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Re: JBM Update: Measured BCs added to bullet library

Great, thanks for the resource. It really comes in handy!
 

Grump

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Oct 23, 2008
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Re: JBM Update: Measured BCs added to bullet library

Whoopi-ki-yi-yayyyyy!!!
 

MitchAlsup

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Feb 19, 2007
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Re: JBM Update: Measured BCs added to bullet library

Brian:

You do good work. Thanks and keep it up.

Mitch
 

glock24

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  • Sep 14, 2006
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    Re: JBM Update: Measured BCs added to bullet library

    Maybe it is just me, but I can't get the program to run with the Litz BCs.

    I select my bullet from the drop-down and the hit 'Calculate'. Nothing. It tells me I still need to enter the BC, bullet weight, and diameter. All the other information is entered correctly as I use this JBM calculator all the time.

    I tried entering everything but the BC, but still nothing. It still says I need to enter the BC.

    Help!
     

    Top Cat

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    Jul 26, 2005
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    Re: JBM Update: Measured BCs added to bullet library

    JBM should insert default values in those boxes. If yours are coming up blank, just put in the appropriate numbers, and any decimal value in the BC box. The calculator should override those entries and default to the correct descriptors associated with your bullet selection anyway, regardless of what you input.

    TC
     

    yavapai kid

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    Apr 28, 2004
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    Re: JBM Update: Measured BCs added to bullet libra

    Bryan,

    I thought your advertised BC for hunting 6.5 140 VLD's was .595.
    I just bought 500 and the boxes say .595.

    Now, on your web site it is telling us,

    0.264 140 0.612 BC (hunting VLD)

    Did you change it? Again?


    Also, I just had Leupold make me up a M1 BDC dial for the LR scope using
    your 6.5 VLD with a .595. Looks like a waste of money now.....
    frown.gif


    Also, on your web site, the bottom pic of the guy with the dead deer.
    It shows him with a rifle barrel pointed at his belly.
    Not exactly a good pic to show in my estimation.

    http://www.bergerbullets.com/Products/Hunting%20Bullets.html


     

    JLM

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    Sep 27, 2008
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    Re: JBM Update: Measured BCs added to bullet libra

    Outstanding!