Regulators for regulating gas that is delivered in discrete charges from a tank that contains compressed gas to a paintball gun, marker, or other application that utilizes or is activated by pressure controlled discrete charges of gas. The regulator has holding, discharge, and fill configurations, controlled by the movement of a piston member in a pressurized chamber, and the activation of a poppet valve on the discharge of the system. One or two low side pressure relief members are provided to prevent the over-pressurization of the pressurized chamber. An externally threaded sleeve member is non-rotatably, but axially slidably received on a distal portion of the body of the regulator so that the sleeve member and distal portion may be axially slidably disengaged, and the regulator can be rotationally positioned so that the pressure gauge is easily viewed by an operator.