Ballistics software that works off YOUR data?

Discussion in 'Long Range Hunting & Shooting' started by EXPRESS, Nov 5, 2011.

  1. EXPRESS

    EXPRESS Well-Known Member

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    I have played with a few ballistics programs, mostly JBM and ballistic FTE (iPhone) and the thing that continually amazes me is that I cannot help to make them more accurate by entering my own data. The predictions only tend to match up for sections of the trajectory, leaving you to tweak BC MV altitude or whatever else you can think of to get it closer to your actual flight, which usually creates more new problems.

    Is there a program that takes your real world tested data and uses it to extrapolate the rest of your trajectory?
    For example you give it zero range 100. Then shoot and record for 300, 500, 700, 1000, enter the atmospheric conditions and let it figure out the actual BC, mV, and fill in the gaps in your trajectory table.

    I have been a little out of touch with the gadget scene so I could be mistaken and su h a program exists, but can anyone point it out to me?

    Thanks.
     
  2. SBruce

    SBruce Well-Known Member

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    That would be nice. I'd like to hear if anyone's come across this also.

    The programs I've played with (NF/Exbal, Sierra and a few different online programs) only allow us to input a poi at a couple of distances and then they will correct the velocity or sight in distance to compensate. They also have ways to change the BC to suit, but it seems to take quite a large change in BC to make much difference.......are published BC's really off by that much.?

    I kinda have the belief that atmoshere, wind changes, light and mirage seem to have quite an impact beyond 1/2 mile. Heck, some cartridges with low BC's are extremely affected once beyond 400 yds. I've got two different altimeters (or pressure monitors, whatever you want to call them) that both give different readings on the same day from the same spot, different by .05 in hg. Which one is correct??........hard to say. Also, I've got two different ballistic programs that each use a different "standard pressure" at my altitude, and one has to be .5 in hg less than the other to give the same dopes beyond 1/2 mile.....which one of them is correct??........again, hard to say.

    Interesting subject, tons of variables.
     

  3. WildRose

    WildRose Well-Known Member

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    No but with most of them you can play with your ballistic coefficient and velocity until it matches pretty closely your actual field data and you can then extrapolate it out to work for any range.

    It won't be precise but it'll be more precise than what you are using now.
     
  4. NomadPilot

    NomadPilot Well-Known Member

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    Excel. It won't tell you mv, bc, and all that (without a lot of work), but that's not really what you want anyway. It'll build an equation to match data points very easily.
     
  5. royinidaho

    royinidaho Writers Guild

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    Respected members are posting on this thread.

    Am I , a guy who has developed drop charts from excel and personally collected field data only recently had a hand-held tool w/ballistic software,hearing that I've done good all along?

    As SBruce said "Interesting subject, tons of variables."

    I use JBM to get a 'start'. Then shoot a bunch of distances to gather data. Then do the excel thing adjusting or eliminating data where shots @ ranges is inconsistent with other data. (it happens . . . more often than one would think.:rolleyes: Who would think that 3 shots in a nice tight group at 730 yds would be so far off the trend of POIs @ other distances)

    I installed a popular ballistics software on the iPod and was so frustrated with it I never got it off the ground. All I wanted was something specific to "my load" instead of tons of superfluous amount of resources for every manufacturer's bullet offerings. I'm a KISS kind of fella.

    I keep my atmospheric data simplified by having only one weather station. What it says, I use. Recording each shot for future study to program the 'puter between the ears.

    Hey, I have one rig spot on drop charted w/varying atmosphere out to 1177 yds at my favorite ambush hide. A handheld ballistic program for the iPod should make it good for "any" ambush spot.:) I would hope!!
     
  6. EXPRESS

    EXPRESS Well-Known Member

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    ...I have been thinking that all it takes is simple graphing software to fill in the gaps and continue predictions, and excel should fit the bill.
    The question still remains, why don't the programmers include the only truly useful feature a ballistics program could have.

    The graph could give you the actual BC of your bullet in your location, for the MV your load produces, then the other variables can easily be factored in.

    Maybe most people who buy ballistics software don't actully ever shoot to test their loads?
     
  7. WildRose

    WildRose Well-Known Member

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    For one thing ballistic coefficients are not static, they change the farther you move downrange as velocity drops.

    There are also so many variables the software cannot account for such as varying densities of air and wind speed/direction between you and the target.

    Just because the barometor reads 29.87 where you are doesn't mean it reads the same at 400, 600, 1,000 etc and just because the wind is coming from a given direction at a given velocity doesnt' mean it's the same throughout the flight path of the bullet.

    You also especially in mountainous areas or areas with deep coulees have to deal with up and down drafts which the softare cannot account for.

    This is why you use the ballistic calculations to give you something to start with and then you go back and plug in varying bc's and velocities to make it match known points of impact and then recalculate from there.

    You just can't come up with enough data to make it actually 100% accurate due to all of the variables you cannot measure or control
     
  8. Nimrodmar10

    Nimrodmar10 Well-Known Member

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    Express
    I'm affraid you're asking for the impossible here. There are many factors that figure into a ballistic program. The variables are almost endless. Fortunately, most of us don't need or want to to take it to the level where we worry about spin drift or corriolis effect on a bullet. Basically we just want to know where our bullet will hit at a second distance when we sighted the rifle at 100 or 200 yards.

    But a ballistics program is still math. It's A + B =C or someting like it. You said you want to tell the program what your drop are for a few ranges and let it figure out the BC, MV and trajectories. That's just not enough data. Give the MV and it can tell you the BC. Or give it the BC and it can give you the MV. Ballistics programs are a wonderful thing but they are just dumb computers. They only count to 0 and 1. We have an old saying in computer programing: GIGO. That stands for garbage in, garbage out. A computerprogram's output is only as good as it's input.

    I use an Android program called "Shooter" on my Droid phone. It even feeds in atmospheric data from the weather sites such as temperature, humidity, barometric pressure, wind speed, gps position etc. But I'm like you, I still shoot my rifles at as many different ranges and conditions as possible and write them down. Sometimes the most important piece of shooting equipment we can have is our dope book.