A paintball marker or other compressed gas firearm is provided including a ram driven by an electropneumatic valve when a trigger is actuated to cause a main valve between a high pressure air supply and a firing chamber to be opened. This ram assembly is independent from the main valve structurally and coupled to the air supply and electropneumatic valve sufficiently flexibly to allow the ram assembly to be operable when the ram assembly is displaced away from the main valve. A bolt is provided for directing pressurized air from the main valve to the firing chamber when the main valve is opened, and with the bolt configured to provide a high pressure air pathway which has a high degree of effectiveness in driving the ball out of the firing chamber without distorting a trajectory of the ball. The bolt can be stationary when air is flowing past the bolt.