If you want a good free ballistics calculator go to the link, go to the ballistics button, then click the English ballistics button. You can put in any bullet you want, change the muzzle velocity, wind direction and speed, and height of scope.

http://www.norma.cc/sida/eng/index.html

A little box will pop up while the calculator is loading. Do not close this box, it needs to remain open for the calculator to run.