A paintball marker with a barrel having a bore dimensioned to receive a frangible projectile. The marker has a receiver defining an interior cavity with a breech area. The receiver includes a flip top portion that is, in some embodiments, pivotally connected to the receiver. The flip top portion is configured to pivot between an open position that provides access to the interior cavity and a closed position that blocks access to the interior cavity. A valve arrangement is provided to selectively allow flow between a supply of compressed gas and the breech area to propel frangible projectiles through the barrel. The marker has a firing assembly configured to actuate the valve arrangement in response to actuation of a trigger.