This difference really only comes into play at extended ranges and has dependencies on caliber, velocity and compass bearing to target.
For example you are shooting a target 1,000M due North using a RH Twist barrel the compensation will be different then shooting the same target with a LH Twist barrel and different again for the same target due south.
As distance increases the number of variables including Spin Drift, Vertical deflection, Coriolis and Magnetic variation become more and more critical. I'm currently shooting several calibers at ranges in excess of 1,500 Metres and you'd be surprised the effect an otherwise insignificant variable has on accuracy.
I won't bore you with the math on powder temp, scope calibration, wind, air pressure, angles etc etc. Punch
http://www.lextalus.com into your browser if you want to learn more about firing solutions.
I don't look at my 50 cal as a rifle, I see it more as field artillery and do the math accordingly