Modeling and Experimental Fragment Impact Testing of the XM25

The XM25 Counter Defilade Target Engagement (CDTE) system is a shoulder-fired weapon that will provide soldiers with an improved capability to engage covered personnel. Cartridges currently available for use are the XM1083 High Explosive Airburst (HEAB) and XM1081 Target Practice (TP). Formal baseline IM tests of the packaged configuration show that the XM25 HEAB cartridges react violently to fragment impact (FI). This is consistent with modeling predictions that the first impacted round should react violently, although the induced shock strength for small caliber items is particularly sensitive to fragment obliquity and hit location error, and the fragment likely breaks up as it perforates the container. The models also predict significant mechanical insult to adjacent rounds should one detonate, both in Fragment Impact and Sympathetic Reaction (SR) scenarios. This is consistent with engineering level SR tests performed for packaged rounds which indicate violent reactions for adjacent and diagonally adjacent acceptor rounds. Several Fragment Impact mitigation strategies are discussed and continuum modeling is used to predict their effectiveness. FI testing of the TP cartridges (inert warhead, live propellant) were conducted to assess the propulsion's contribution to the reaction violence. While responses to the TP tests were generally benign, in all these tests the lid was repeatedly thrown a significant distance from the test stand. Containers with inert simulants were tested against FI threats to determine the debris throw expected from the fragment momentum alone, and the results compared with high-rate continuum modeling. It was determined that the small arms propellant used in both rounds was, by itself, able to project hazardous debris under fragment attack.