Hard sound rifle
From Halopedia, the Halo wiki
Template:Weapon A Hard Sound Rifle is a Human sonic weapon used to stun or kill a target. As it utilizes concentrated sound waves instead of a solid projectile, a hard-sound rifle leaves no residue or powder burns and causes little noticeable external damage to the intended target, making the weapon virtually untraceable. A preferred weapon used for assassinations by the Office of Naval Intelligence, they are sometimes purchased illegally by civilians for less malevolent means.[1]
