Abstract: A buffer comprising a plunger slidable in a ported tube. A metal tubular member circumferentially surrounds that part of the ported tube in which all the flow resisting ports are formed and is the radially inner wall of an annular space filled with compressed gas. The outer wall of an annular space is formed by a tubular membrane. The annular chamber between the ported tube and the metal tubular member is part of a low pressure reservoir of the buffer and communicates via an annular passage in the closed end of the buffer with the remainder of the reservoir which is an annular chamber formed between the tubular membrane and the outer tubular wall of the buffer. The metal tubular member shields the tubular membrane from the damaging effects of jets of liquid forced through the flow resisting ports during compression of the buffer.