Abstract: A recoil assembly for an automatic firearm, including a reciprocating bolt and carrier assembly, has a hydraulic buffer to provide a reduced rate of fire and prevent wide fluctuation in the round to round rate of fire. The buffer includes a piston which pushes hydraulic fluid through an orifice when depressed by the bolt and carrier assembly at the end of its recoil stroke. When the bolt and carrier assembly begins to displace the piston, hydraulic retardation is immediate. A spring loaded sliding seal pushes the hydraulic fluid through the orifice during the return stroke which returns the piston to its original extended position. The buffer also prevents carrier bounce and promotes a mild recoil shock.