A hydraulic recoil buffer assembly for a firearm having a receiver and a fixed or collapsible stock assembly including an end cylinder adapted to be secured to the pistol grip or receiver of the firearm and slidably translatable with respect to the extension tube, and a hydraulic shock absorption assembly operative to produce a hydraulic resistance to a rearward movement of the end cylinder during recoil of the firearm. The hydraulic shock absorption assembly has an orifice restricted fluid flow passage and a piston head that compresses a return spring as the end cylinder moves rearward against a recoil coil spring. The recoil buffer assembly stores a portion of the recoil energy through compression of the recoil spring and the return spring, and dissipates a portion of the recoil energy through the resistance provided by fluid flow through the orifice restricted flow passage.