I've been looking at the ballistics calculator on the Hornady website that uses all of the common varibles (i.e., sight height, cross wind, barrimetric pressure, etc.) and was wondering if anyone in here has the actual formula on hand that can be plugged into an Excel spreadsheet.

I don't have the skills to hack into their site & I would like to be able to do the same thing on my PC at the loading benchwithout going online.

Thanks,
MLG

Too many variables for me at least to have on spread sheet. Not smart enough or motivated enough when I can use Shooter program on Android or Sierra ballistics calculator.

I know items like BC add up. I would for go bullets to have manuals and other needs rather than walking bullets down range.

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There are a lot of variables like BC, temp, humidity, spin drift, wind in your position, halfway to target, and at the target, etc.. I suppose you can look through physics, fluid mechanics, and some differential equation books to find a set of equations to get close based on your bullet, muzzle velocity, scope hieght, etc...

I would imagine it would be a set of 3-dimensional differential equations that you would have to solve simultaneously to determine the closest equation. You would need a 3-d fluid mechanics simulator program to help.

I tried using published data from Nosler to do a curve fit and find an equation to extend the range, but that information would not be completely accurate past the published data.

Yes, I am an engineer.

Hate to disagree with PKT1106, but.... you don't need to solve these things from "3-dimensional differential equations"....

All you need is a good exterior ballistics text book. Exterior ballistics isn't as sophisticated as you heard above once broken down into parts. The codes you are interested in don't require equilibrium or convergence algorithms.

While complex physics models exist, most ballistics programs are done with empirical data, not with raw physics.
The physics researchers concern themselves with such matters, but fire-control and ballistics folks are a little more practical.

For example. Any of the physics fields with lots of natural dispersion and friction, can be mathematically daunting. I can try to predict flow friction or wear, but mostly I tell folks to use a friction or wear coefficient that I generate in a lab.
Suddenly, 12,000 lines of code dropped into one simple line that gets them to "good enough".

BTW, if you really have the inclination to program this yourself, you will probably not need any help from a forum.

It isn't expensive to buy exterior ballistics software or just use the shareware on the web.
If your time is worth anything at all, you won't try writing this many macros from scratch, however....
If your passion is writing algorithms and you don't want to buy something, the older reference books are usually available at the bigger libraries.
The International Ballistics Society is a good reference, but the better current books are known to be expensive.

http://www.bfxyz.nl/


I see AeroE beat me to it....

Here's what I use.

http://webpages.charter.net/tyoberg/upload/Ballistics_Calculator97.xls

Holey Crap!!!!!!!!!!  We may have moved waaay beyond me and spreadsheets there!
I'll give it a try but I may just have to stick to the ballistics data in the back of the book.

Thank you for sharing AeroE.  Your abilities exceed the average with that one.
MLG

I use the RCBS.LOAD Ballistic tool, it's about the best one I have seen or used but cost ~$100+ for the program, it also gives you every load data manual old and new and an updated bullet list with most every bullet imaginable and a great cartridge designer tool that I've used a few times alone with many other tools and features. The program was designed a while back but they do a good job keeping it updated plus you can add user data as well for bullets and cartridges that are not available, I would like to see a newer version one day but I do really like this one and have it on every computer I have.  

A view of the ballistic tool with a 6.8 load I use

Here's a free add-in for Excel. Also, JBM is a great source for exterior ballistics info.

 

You'd be the first...LOL. I know what you are saying, though. Yes, there is already data and general curves from companies, I thought he already knew that. I was thniking he was looking for something deeper/more comprehensive and barring what is already out there, one would have to develop their own equation.

Thanks for not taking it the wrong way PKT1106.

Cheers.

The ballistics is based o na standard model bullet that has been fired and measured, abd the results are then adjusted to other bulets and conditions.

It is not actually a single equation, but a set for the adjustments,

The standard projectile data is a table, not an equation.

I downloaded "Shooter - Ballistics Calculator for Android" for my XOOM tablet which I can easily take to the range. It uses much info from Litz's book which I have. Did not find an equivalent for iPad. Shooter calculates and displays tables and graphs just like the windows calculator that comes with Litz's book.

Aero I use it on one of my laptops that has Vista with no problems, I don't think I had to do anything special to make it work(ver. 3.36) but if your having problems I'm sure you can run it in compatibility mode set to run as Windows XP SP2 and it will work just fine, although I just checked mine and it's not running in compatibility mode and works just like my other laptop with Windows XP.

Maybe I had to run it as an Administrator or something to get it to work, I know when I update the program I have to close it and open it back up as an Administrator before the update download will complete and then the update also has to be ran as an Administrator for it to function properly. After that the program works without issue, for me anyway, I know computers have a mind of their own sometimes.

ETA: My original disc is Ver. 3 and Ver 3.36 is after the update

Wow, that's nice.  Your own creation?

I'll have to check out the Hornady program, I've never used it.

No, but I bent it somewhat to do my bidding (I added the rosettes).