Proof-Testing the Physics Applications Inc. 50-mm Laboratory Gun
Abstract
Reported here is the effort to proof-test a newly acquired breech and assembly for the 5O-mm high-pressure powder gun for terminal ballistic testing in the U.S. Army Research Laboratory's (ARL) Range 309A (R309A). The performance of a custom-produced 0.012-inch web 7-perforation M30 propellant in routine use there was modeled by the ARL-developed one dimensional (1-D) interior ballistic code IBHVG2 to select a propelling charge mass (CM) that would produce a pressure of approximately 130 ksi for the purpose of proof-testing the gun. Proof slugs of the appropriate mass, 900 g, were fabricated. The breech end was assembled to a scrap 0.6-m piece of barrel to add mass, mounted in a hastily built fixture, and fired without recoil system at ARL's barricaded Range 18. The priming system and recipe supplied with the Physics Applications Inc. (PAI) breech end was adjusted until a pressure time (P-T) curve with acceptably low-peak negative differential pressures was obtained. This required reducing the propellant In the 0.SO-cal. case used as a primer and putting Benite strands in the spit tube. Following establishment of a suitable priming recipe, the pressure was raised from 50 ksi to 120 ksi in steps, resulting in slight, permanent plastic deformation of the chamber and inducing a favorable state of residual stress (autofrettage). The assembly was nondestructively examined for cracks before and after the proof-test procedure, and no reportable indications were found. This report briefly describes the hardware, the rationale behind the proof-test, the mechanical response of the system, the Interior ballistics, and the results. Extensive instrumentation was used during the tests, and the results are tabulated and plotted.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1998
- Accession Number
- ADA354408
Entities
People
- Graham F. Silsby
Organizations
- United States Army Research Laboratory