One Approach to Assess the Aftereffect Period on a Projectile and on the Bottom of an Artillery Gun Bore

The time of shell projection from the barrel of an artillery gun, according to classical approaches of thermodynamics and internal ballistics with period correlation on the calibers of domestic artillery weapons, is well studied. Clarification of the most important ballistic and energy characteristics requires refinement for modern weapon systems. The purpose of this article is to propose an approach to estimate the aftereffect period on a projectile in the form of matching the second consumption of powder gas, the polytrope coefficient and the ratio of the projectile current position area to the total area of the barrel bore when passing the breech section.The possibility of a more accurate study of the aftereffect period using a gas-dynamic approach by clarifying the ballistic and energy characteristics adjusted for the aftereffect period is being investigated. The estimation of the second consumption and the polytrope indicator is given using the example for the data of the 12.7 mm machine gun of the Second World War DShK, the modified Utes and Kord machine guns, the 7.62 mm Kalashnikov assault rifle, the 9 mm Serdyukov Gyurza self-loading pistol, the 9 mm Makarov pistol, the domestic 10 mm smoothbore weapon, the 11.43 mm Thompson submachine gun, the 11.43 mm Automatic Colt Pistol and the domestic smoothbore service 132-caliber DOG revolver with 12.5´35 mm ammunition. Energy and ballistic characteristics are confirmed by a diagram of the effective use of shot energy and a diagram of the direct target hit range. The proposed grapho-analytical approach is recommended to be used to clarify the energy and ballistic characteristics of the barrels of domestic artillery guns, taking into account the aftereffect period.