BAE Systems is currently developing and testing a 155 mm advanced gun system (AGS) and a long range land attack projectile (LRLAP) as a part of the DDG-1000 ship development program. For this development, it is important to understand the barrel and projectile dynamics, including the interaction of the barrel and the projectile in the bore as well as the projectile tip-off parameters at exit. An abaqus explicit dynamic finite element model has been developed to compare results with test data that were taken on June 18, 2003, at the BAE Systems site at the Alliant Techsystems Proving Ground (ATPG) during AGS propellant testing. The abaqus model includes the gun barrel, the projectile used for propellant testing (a steel slug), the M110 gun mount, and the recoil system. Features of the model incorporate settling of the barrel due to gravity, gun recoil, in-bore interaction of the projectile and the barrel using contact surfaces, and the initial flight of the projectile after bore exit. The abaqus model results have been compared with gun firing test data acquired during propellant testing at Elk River, MN. These comparisons include barrel and projectile displacements, angular velocities, and axial accelerations. The abaqus model results are also compared to similar models of the test conditions with the simulation of barrel dynamics (simbad ) gun dynamics code and the ibhvg 2 interior ballistics code.