Temperature compensating electro-mechanical ballistic control tube system

Abstract

A temperature compensating ballistic control tube system for varying the volume containing primary propellant, for the purpose of affecting the effect of the propellant on the projectile in order to compensate for the effect of ambient temperature upon the performance of the primary propellant. The volume containing the primary propellant is changed by pushing the projectile away from the casing containing the primary propellant, down a gun bore by a piston of the ballistic control tube. The piston, pushing the projectile, is moved by an ignited secondary charge in the ballistic control tube. Electronic components detect initial movement of the piston and projectile and, after a certain delay, ignite the primary propellant thereby ejecting the projectile from the gun. A typical primary propellant, within a given volume, is temperature senstive, that is, it provides more force to the projectile at higher temperatures. Increasing the volume, by moving the projectile with the ballistic control tube piston before igniting the primary propellant, reduces the performance of the ejected projectile in accordance with an amount of delay inserted between the moments of initial movement of the piston and ignition of the primary propellant. The projectile is moved more prior to primary propellant ignition, at warmer temperatures so as to further increase the primary propellant volume since the cartridge is designed for maximum projectile performance at cold temperatures.