US Patent 8429845 Modular integrated rail system including a dampening device

A modular integrated rail system for a firearm includes a dampening device for absorbing shock waves and dissipating harmonic vibration generated by a firearm. The modular integrated rail system includes an upper hand guard, a clamping assembly configured to releasably clamp the hand guard to the firearm, and a dampening structure disposed within a cavity formed in the hand guard. The cavity has opposing fixed end walls, and the dampening structure is captivated between the opposing fixed end walls of the cavity.