This work was carried out to study the possibility of using double base propellants in guns working with single base propellants and vice versa. This was done through studying the effect of changing powder type on the internal ballistics parameters (gases pressure, projectile velocity and gases temperature) through the gun barrel with changing the grain configuration. Two types of guns were studied (155mm howitzer and 100mm field guns) with two types of powder (single base -M1-MIL-P-309-and double base -M8-JAN-P-381propellants). Three grain configurations (cord, stripe and single perforated grains) were used for different cases. Computer program (MATLAB) was used to obtain the required results after checking the reliability of the program. The results emphasize the effect of changing powder type on the ballistics parameters through the gun barrel. It was found that it is possible to obtain the required muzzle velocity without exceeding the maximum gases pressure by adjusting the dimensions of powder grains and weight of propellants putting in mind the length of barrel.

Howitzer Gun is a type of large-caliber artillery gun that typically utilizes a mixture of propellant grain shapes to control the burning inside the gun, and to impart the prescribed velocity to the projectile with the smallest mass of charge without exceeding the maximum allowable pressure. In this paper, a mathematical model has been developed to predict the main internal ballistic parameters i.e., Maximum Pressure (Max. P) and Muzzle Velocity (MV) for artillery howitzer guns. The propellant charge utilized is a single-base propellant using a mixture of dual-shape grain namely, tubular and multi-tubular seven-hole shapes. The mathematical model was solved numerically using the Runge-Kutta method in MATLAB environment for a 130 mm howitzer field gun which was chosen as a test case. The simulation results were obtained in terms of several plots showing the effect of grain shape and grain mixture ratio on the Max. P and MV along the gun barrel. Furthermore, the optimum mixture ratio gives a slightly reduced MV with a significant reduction in Max. P has been determined graphically and compared with experimental data taken from the test firing of the gun. The simulation results showed good agreement with the experimental ones (less than 10% numerical error). The proposed model can be used in the analysis and optimization of other similar gun systems taking into account the right input data for both guns, and propellants.