Which is better -Field Data or a Ballistic Program?

[brown dog]

I'm always a little cynically amused when I see posts asking which program is better than which; or hear individuals stating that 'field data' always trumps data from a ballistic program.

 

The bottom line from any program is crap in crap out; almost anything on the market will be correct if you model your system correctly.

 

Whereas

 

Nothing on the market will be correct if you're just putting in BC, sight height, mv, zero distance and manufacturer's stated click value.

 

You must calibrate your whole system;......and that's why it's only snake-oil salesman who will claim to model your bullet's flight for you without quality field drop data obtained from your rifle and using your scope ...coupled with an understanding of the effects of atmospheric variables - note Lindy's comment on pressure in the article linked below.

 

I think Lindy's article is rather good (one or two very minor things I'd quibble about - for eg Lindy is obsessed with labelling coriolis as eotvos - eotvos is actually the gravitational weight change of objects moving West or East and not at all what matters with E -W fire at varying latitudes - what matters is Coriolis, and it relates to the vector effects of firing on a rotating sphere)

 

Enough of that; here it is, good stuff:

 

http://www.arcanamavens.com/LBSFiles/Shoot...loads/Programs/

 

I'd also like to quote Bryan Litz in a recent post on SH (from which I also stole the link) who says it rather better than me:

 

Ballistics is a mature science, and solvers like JBM are implementing the science correctly. So if you fully understand how to use the program, and all your instruments are calibrated (chronograph, kestrel, etc) and you give the program accurate inputs, the output WILL be accurate.

 

There's another 'gotcha'...

Will you use the data properly? Meaning, do you understand how much your scope reticle actually moves each click? If you're assuming it moves 1/4 MOA per click and you haven't ever checked it, it's not fair to conclude that the program is giving you bad dope. It might be the scope that's not applying the right dope.

 

So to answer your question and to echo the answers above:

Yes the program is accurate, and

Yes it's common for shooters to 'observe' different trajectories than predicted because of imperfect application.

 

The more careful you are about your application and the more you know about ballistics, the closer your predicted and actual trajectory will be.

 

 

So; crap in crap out

 

The bottom line is that if you know (understand) what you're doing; your ballistic program WILL be spot on.

 

Whenever you hear someone saying 'field data is better than any ballistic program' just smile; they're actually telling you that they don't understand ballistic prediction

[Deserttech Europe]

Field Data (real world data) is never the answer for long distance ballistics, however this needs some definitions.

 

The real world measuring on a metre stick of turret calibration I refer to a laboratory experimentation.

 

The data required when shooting down a valley in a storm is real world data and irrelevant when compared to ACCURATE data entered into a good ballistics model.

 

 

Regards

 

DTA