how do u find the ballistic coefficient of a bullet

[nova_scotian_guy]

how do u find the ballistic coefficient of a remengton core lock 180 grain 308 round???

 

[CanAm]

You need two chronos and there is a calculation you do based on the change in velocity over a given distance, which is then averaged for a string of shots.

 

[na1lb0hm]

http://en.wikipedia.org/wiki/Ballistic_coefficient


but the remmy site shows:

PRC308WA Premier® Core-Lokt® Ultra 150 Core-Lokt® Ultra Bonded 9 1/2 0.331

 

[MarkHFX]

Ballistic coefficient of Remington Core-Lokt 180 grain .308 bullets is .248

edit (oddly I got as many 331 results as 248 na1l. Not sure what's up with that)