Characterization of natural and recoil-induced vibration of an AR-15 rifle at the cheekbone-stock interface

Abstract

Effects of sound pressure and shock on hearing loss have been widely studied. Studies involving direct assessment of sound pressure levels and influencing variables related to rifle discharge, especially with respect to standard military small arms have mostly focused on the effects of external pressure on hearing. Other studies have characterized physiological effects of external vibration on animals and humans. Shock phenomena and high-pressure waves have been linked to effects from gradual changes in tissue thickness to traumatic brain injury and other central nervous system maladies. Rifle shooters, including soldiers, law enforcement officers, and hunters, typically shoulder rifle-type firearms in a way that puts the buttstock in direct contact with the cheekbone, known as the “cheek weld.” This work experimentally characterizes the vibrations experienced by the shooter at the cheek/buttstock interface, and discusses expected physiological and acoustical effects as a result of conduction into the skull.