Relationship of Residue Formation to Wax Used in M203 Propelling Charge Liners
Abstract
Recurrence of residue problems with the 155 mm M203 propelling charges led to an investigation of the wax used in the wear-reducing additive liner. Laboratory investigations indicated that the currently used wax, Indramic 170C, softens substantially under firing conditions, whereas Polywax 655 is substantially more brittle. A mechanism for liner breakup is proposed which suggests that, at the temperatures encountered during firing, a brittle liner would be dispersed more effectively and the frequency of the residue would be reduced accordingly. The results of the test firings were consistent with the proposed mechanism for liner breakup. The charges made with Polywax 655 produced the least residue under all conditions. Factors other than the choice of wax which increased residue frequency were: higher tube temperature, longer chambering time, ray/lead laminate as the liner substrate, and increased amounts of dacron staple in the liner. Since these factors tend to decrease liner brittleness, their effect is consistent with the proposed mechanism for liner breakup and residue formation. Charges using Polywax 655/scrim in the liner have been shown to be free of residue when fired in gun tubes up to 149 C (300 F) with chambering times under 30 seconds.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1979
- Accession Number
- ADA081716
Entities
People
- D. S. Downs
- L. E. Harris
Organizations
- United States Army Armament Research, Development and Engineering Center