10/50 yard zero AR15 ballistics software program?

[JC JC]

After researching the 50 yard zero at 10 yards (for AR-15), it seems that the 1.9" offset was calculated using a 2.5" center of bore to center of optic measurement.
Some sort of ballistic program was used to determine this 1.9" offset.
Can anyone link me to the software program?

I would like to calculate different offsets.

 

[RifleDude]

I really like the on line JBM calculator. Just use any of the trajectory calculators and plug in your cartridge and rifle information and you're good to go.

http://www.jbmballistics.com/ballistics/calculators/calculators.shtml