The influence of impact velocity on bullet trajectory deflection through ballistic gelatine

This paper presents the results of a study on bullet trajectory deflection, for 9 mm Luger Full Metal Jacket Round Nose (FMJ-RN) bullets fired through 23–24 cm of ballistic gelatine. The bullets were fired at different velocities. Impact velocity, energy transfer and bullet trajectory deflection after gelatine perforation were measured and calculated. As was expected, energy transfer to the gelatine blocks generally increased with increasing impact velocity, indicating an altering bullet/gelatine interaction with altering velocity. This alteration did not result in a discernible alteration of bullet trajectory deflection. Deflection angles fell between 5.7° and 7.4° for 136 of the 140 fired shots, with four outliers below 5.7°. •Bullets transfer kinetic energy when passing through gelatine.•Energy transfer increases with increasing impact velocity.•Round nose bullets deflect when passing through gelatine.•Trajectory deflection does not increase with impact velocity.