Thread: Differences between Trajectory Simulators

Having run the same inputs for my long range load through the JBM Ballistics and Applied Ballistics online calculators, I've found a disconcertingly large difference between the two in predicted drop of around 200mm at a range of 800m and 350mm at a kilometre, equivalent to a difference of 50 ft/sec in muzzle velocity.

Have you also come across differences like this between trajectory simulators, and if you have then what online or PC-based calculators (not apps please) have given the best match to observed drop and chronographed MV data for you please ?