A Consumable Case for Artillery Systems.

Abstract

Abstract : The inherent lack of rigidity and the complexity of bagged propelling charges and the associated ignition components can lead to incorrect alignment and/or assembly of the charge. A well-designed consumable case can alleviate these problems by assuring ignition system alignment and control of charge location within the chamber while simplifying the fabrication of the charge. A howitzer prototype consumable case was fabricated from available felted nitrocellulose components and test firings were conducted. Three types of ignition systems were tested: a base pad and centercore snake of black powder (as used in the M203 Propelling Charge), a centercore snake alone (113 g Class 5 black powder), and an igniter constructed of 113 g of Class 5 black powder placed in three 1-cm diameter plastic tubes within the centercore tube. The results indicated: 1) the consumable case gave performance comparable to the M203 charge; 2) the base pad/snake igniter gave larger pressure waves than the two types of centercore igniters alone; 3) the igniter system based upon the plastic tubes gave the best performance; and 4) there was no significant increase in residue with the consumable case. The rigidity of a consumable case and the precision of the manufacturing process should eliminate the persistent problems (e.g., ignition delay, pressure waves, velocity variation, etc.) which are the result of the misalignment of critical ignition train components and poor tolerances inherent to bagged charges. Therefore, major benefits of a consumable case should be improved safety and precision as well as good automatic handling and loading characteristics.