Some embodiments pertain to a projectile that includes a propellant and a casing that encloses the propellant such that the casing acts as a reaction chamber during flight of the projectile. The casing includes a plurality of flechettes. When the projectile strikes (or is near) a target, a large internal sheer pressure forms within the casing. This sheer pressure causes the flechettes to sheer apart at the thinnest sections of the casing. Once the thin sections of the casing are sheered apart, the flechettes will be unconstrained such that the flechettes take individual flight paths.