The software for support of external ballistics calculation for weapons of 7.62 mm caliber is described taking into account external factors for the optical-electronic tactical exercise machine for small arms "Inhibitor" developed at the Institute of Mechanics UdmFRC UB RAS and at Computer facilities department of Kalashnikov ISTU jointly with JSC «Kalashnikov» Concern». A tactical and technical task is given for ballistic calculation of the trajectory up to 2 km of range of weapon simulators with a laser emitter of the targeting point taking into account external factors: types of sights, especially optical, ballistic scattering of bullets, deflection of the bullet from the side wind and derivation, which have a significant impact on the ballistic trajectory. The implemented differential mathematical model of external ballistics relying on the aiming angle of the weapon simulator depending on the sight readings, the initial speed and ballistic coefficient of various types of ammunition in real time builds a ballistic trajectory with adjustments for the air temperature and pressure and dependence on lateral wind and random dispersion of bullets to further solve the "problem of meeting" with obstacles. The given results of software tests for the error in calculating the coordinates of the ballistic trajectory showed full compliance with the requirements and adequacy of mathematical models. It was concluded that further research and development of electronic shooting simulators were promising thanks to the improvement of computing tools and the development of software libraries in order to increase the accuracy of simulating external ballistics of simulators taking into account many external factors, expand functional networks and reduce cost and, therefore, increase competitiveness.