Hi all,
does anyone have the formulas needed to calculate exterior ballistics, especially velocity and bullet drop. I found only spreadsheets to calculate that for one cartridge, but I want to do that in excel for several hundred cartridges in a single sheet. Any help would be appreciated.

Wolfgang

The question is a bit...how shall I say this...not resting on the foundation of understanding?

The issue of drop is essentially time of flight. That of velocity is a matter of barrel length and quality working in concert with case capacity, charge weight, expansion ratios, and on and on and on...

So, if you start with a given velocity you only need to know ACCURATE Ballistic Coefficient information for the bullet, or Coefficient of Drag curves, then you can spread sheet forever. It is however, a matter of garbage in, garbage out, as you may not actually have accurate BC information, and Cd info is not readily available for small arms bullets. You may find some satisfaction with this site:
http://www.eskimo.com/~jbm/ or maybe this one: http://www.jacksonrifles.com/ballistics.htm or even this one: http://www.loadammo.com/ or maybe not. Don't know if this helps or not, but good luck anyhoo.

Here's a user friendly on-line ballistic calculator:
http://www.biggameinfo.com/BalCalc.aspx

Val,
thats a beautiful calculator but online. I want to do that in a sheet for more than 500 loads to compare them. So, online calculation is not what I desire

DigitalDan,
I checked the links and hope to understand those formulas. It`s very clear, that I start at a given velocity and want to use the formula to calculate the velocity decrease, that gives me the KE at several given distances. Further knowing the velocity decrease I want to know the bullet drop. Surely, I need the BC of every bullet but I have to do the calculation for every load in one single line. Having done that, it`s very nice to play in that sheet with the filter function to compare the different cartridges. It works till now only with their basic data as velocity, energy, SD, bullet weight but it`s a lot of fun. Having all the ballistics data, you can compare bullet drop at a given distance or energy. We will see if I can work that out.

Thanks so far for your help!

Wolfgang

Back in the winter I did some research on this because I wanted to set up my own spreadsheet to calculate trajectories, drop, energy etc. As I recall I found the mathmatics in "Understanding Ballistics" by Robert A. Rinker published by Mulberry House Publishing Company, P. O. Box 575, Corydon, Indiana, 47112, U. S. A. Tel. 888-738-1567. You have to read the book and then go back after each aspect of what you want to do.

I set up the math formulas for the various characteristics I wanted, but I never got around to setting up the spreadsheet. Partly that's because I was thoroughly familiar with "Symphony" spreadsheets on old IBM hardware and I just hate the Microsoft spreadsheets by comparison. I would have to look around my basement to find the math, but I do have it somewhere right next to some other stuff I can't find. Hope this helps!

Wolfgang:

I coded the basic "point mass method" from McCoy's excellent book in Matlab, using the ordinary differential equations solver included in the basic package. I wanted to do just what you want to do, which is to look at various external effects on long range performance across a bunch of different initial conditions. It matched the output from both RSI ShootingSoftware and QuickLoad's Quicktarget.

I just recently did another differential numeric solution for someone else, and coded that in Excel via the built in Visual Basic. Now you have me thinking that I may take a shot at coding the ballistic calculations in VB. It will do exactly what you want, and would end up being a function built into Excel. Email me if you want to know more.

Cheers,

Chris

Hi all,



thank you for your help and suggestions! On one mentioned page I found an excel sheet from jacksonrifles.com, that I reworked to calculate the basic exterior ballistic data for nearly 600 different cartridges and loads up to 400 yds. I`m still fine-tuning the sheet and maybe will post it one day.



Wolfgang