Assessing the Risk of Bullet Ricochet from Waves

Abstract

In both littoral environments and the open ocean, assessing the risk of bullet ricochet from the water surface is important as friendly assets and possibly civilian infrastructure may be in close proximity to operations. Bullet ricochet from water is usually examined in a laboratory environment where bullets are fired at a level water surface. While this set-up is appropriate for replicating ricochet from ponds, puddles, or small water containers, it is less applicable to ricochet from large bodies of water that support a rich surface wave field. Here, a method is proposed to extend results of flat-water experiments to consider bullet ricochet from a wavy surface. It is shown that the critical angle above which ricochet does not occur and the likelihood of stable or tumbling ricochets depend on whether waves are present and in what direction those waves are traveling relative to the path of the incoming bullet. Modeling suggests that the risk of ricochet is reduced when wave crests are perpendicular to the direction of fire but waves also increase the variability of ricochet characteristics. It is therefore suggested that, when possible, wave effects be considered when assessing the risk of bullet ricochet from water.