Statistical Approach in Determining Energy Ballistic Parameters of Gunpowder Contained in the 7.62×39 mm Ammunition Based on Measuring the Development of Pressure in a Manometric Bomb

Currently, most design processes are carried out with the use of specialized tools in the form of advanced computer programs. Assuming that mathematical models are formulated without significant simplifications and their numerical solution is performed with high accuracy, the quality of the problem solution is determined each time by the input data. In the case of the main problem of internal ballistics, these will be the reliably obtained energy-ballistic values of the gunpowder. In the present work, classical methodology for determining the energy-ballistic parameters of gunpowder based on the recorded pressure curve in a manometric bomb was implemented using mathematical statistics. For the assumed distribution of the probability function, which is the Student’s t-distribution, confidence intervals have been established for the assumed confidence level for the values of the parameters of the distribution of ballistic features, such as the loading density power, gunpowder force, covolume and proper burn rate. These parameters were determined for three different gunpowder charges contained in the cal. 7.62x39 mm ammunition: SM FMJ 8 g, Barnaul FMJ 123gr 8.1 g ZN FMJ and STV FMJ-CIP 8gr/123grs.