Gun Barrel Erosion Analysis Using a Coordinate Measuring Machine (CMM): Experimental and Statistic Study

Abstract

This paper focuses on the development of an analytical model to predict the engraving pressure evolution and the chamber volume in terms of the inner barrel profile in different weapon life stages. The test barrel “12.7x99mm NATO†is considered. First, a coordinate measuring machine (CMM) with a contact scanning probe is used to measure the inner dimension of the barrel in its different life stages. The CMM parameters; such us (i) the measuring force, (ii) the measured points, (iii) the scanning velocity; are investigated. In order to ensure minimum measurement incertitude, a statistical analysis is adopted to select the reliable CMM parameters combination. Second, piezoelectric sensors with a special doppler radar are considered to measure the (i) pressure, (ii) bullet velocity and, (iii) engraving pressure in the test barrel. Thus, based on analytical theories, a predictive algorithm is elaborated to match the inner barrel profile to the engraving pressure.