US Patent 10415907 Firearm buffer with biasing member

A buffer assembly for a firearm includes an internal assembly comprising a plurality of weights and a dead-blow biasing member in the form of a coil compression spring, stack of wave washers, a compression washers, or a compliant portion integrally formed in a rear end cap of the buffer assembly. The dead-blow biasing member is positioned between a flat end of one of the weights and a rear end cap of a buffer body or between flat ends of adjacent weights.