Abstract: Two embodiments of a compressed gas gun are disclosed. In the first embodiment, a slidable barrel supported by two barrel guides is employed. A thermoplastic compression sleeve provides a bearing for the slidable barrel, which impacts a valve assembly upon actuation of a trigger mechanism. The impact momentarily opens the valve thereby releasing compressed gas and expelling a projectile. An anti-rebound lock prevents rebound of the barrel and subsequent discharge of gas. In the second embodiment, a slidable bolt assembly serve the function of impacting the valve. The barrel is rigidly attached to the frame of the gun and a spring forces the slidable bolt assembly against the valve. A seal is provided between the slidable bolt assembly and the barrel for allowing slidable movement and preventing the loss of compressed gas.