Artillery trajectory simulator programs can produce detailed output that may be tailored by the user, including parameters displayed and sequence of presentation. Here we consider the General Trajectory (GTRAJ) program developed by the US Armaments Research and Development Center. The GTRAJ model has been used in the evaluation of Army meteorological systems in terms of artillery parameters such as radial miss distance and probable circular error. However, the processing of the output was tedious and is not efficient for large numbers of GTRAJ output files. The method described in this report semi-automates the process and greatly reduces the time and effort required. Results of several trial runs demonstrate the value of the method for several GTRAJ output files. The programs were written in Python (version 3.5) and would require some modification for different forms of the GTRAJ output files. However, the program described here can serve as a template for other GTRAJ output files.