## Recent posts

#1
##### Updates / Dec 2021 Recompilation
Last post by admin - December 29, 2021, 11:12:59 PM
I have recompiled bfx.xll, bfx64.xll with Visual Studio C++ 2022
#2
##### Worksheets / Approximate ballistics formula...
Last post by gvp - February 23, 2021, 09:09:31 PM
An excel implementation of the following article.
https://www.sciencedirect.com/science/article/pii/S2214914717301459

See attached excel file.

Happy shooting ...
#3
Last post by admin - February 16, 2021, 08:57:30 PM
one can specify that one wants to use the density of a certain material in BfX_Bcs, eg =bfx_bcs(1;"Cu/m^3";0,5;"in") calculates the ballistic coefficient of an 0.5 inch copper round ball
#4
##### Updates / Update uploaded Feb 2021
Last post by admin - February 11, 2021, 08:57:33 PM
Today I have uploaded a freshly compiled version of BfX.
Furthermore I have added a BfX_Bcs(density of bullet;diameter of bullet) to compute the ballistic coefficient of spherical (round) bullets. These can be used in combination with the GS drag function.
The new version of Getting Started.xls(x) illustrates computations with BfX_Bcs.

E.g the velocity of a .50 inch lead round ball, with muzzle velocity 2012 fps at 100yd: =BfX_Vx("fps";2012;"fps";100;"yd";BfX_Bcs(0,41;"lb/in^3";0,5;"in");"GS") (which would result in 1046 fps)
#5
##### Updates / New update coming soon
Last post by admin - February 10, 2021, 11:08:49 PM
I have added bfx_Bcs
That computes the ballistic coefficient of spherical bullets.
I have to updated  the "Getting started" to and check some other things in the code
Lydia
#6
##### Ballistics / Re: Shotgun Ballistic Calculat...
Last post by admin - February 10, 2021, 04:09:34 PM
by the way,
bfx looses accuracy for elevations above 15 degrees. In practice this affects max range / long distance calculations.
#7
##### Ballistics / Re: Shotgun Ballistic Calculat...
Last post by admin - February 10, 2021, 03:07:15 PM
e.g.  .50 round lead ball bc= 0.107 lb/in^2
#8
##### Ballistics / Re: Shotgun Ballistic Calculat...
Last post by admin - February 10, 2021, 03:01:36 PM
I have (re)done the research.

The ballistic coefficient is computed from m/(d*d) where m is the mass of the pellet in lb and d its diameter in inch

or bc = density*pi*d/6

density lead = 0.41 lb/in^3
density steel = between 0.280 and 0.291 lb/in^3
The drag function to use is "GS" in bfx which matches the one in the above link

#9
##### Ballistics / Re: Shotgun Ballistic Calculat...
Last post by admin - February 09, 2021, 10:49:05 AM
I couldn't resist googling. Since 2008 some scientific papers were produced on the matter. https://www.sciencedirect.com/science/article/pii/S2214914717301459 has an interesting one which I quickly scanned
you can use it to check your table.
Next posts on the bc calculation
#10
##### Ballistics / Shotgun Ballistic Calculator
Last post by gvp - December 21, 2020, 01:15:46 AM
I've made a very simple excel file in order to calculate Velocity, Energy and TOF for shotgun BB's.
1. What is the BB's ballistic coefficient ? Can it be calculated ?
2. Any idea how to make this simple excel file more reliable according to atmospheric conditions and the subsonic, transonic and supersonic region ?

Thank you in advance,
Bill