A floor drive drilling system comprising a pipe drive bushing having a frame and a rotor which is raised and movable to and from a master bushing by wheels and lowered and coupled to the master bushing for rotary drilling and reaming. The rotor is driven by the master bushing and has a plurality of gripper assemblies which selectively engage the drill string to transfer torque thereto and are movable upward and downward a selected distance for drilling and reaming. Each gripper assembly comprises actuating rings and jaws for gripping and ungripping the drill string. Frictional inserts with large surface areas and grooves are positioned on the jaws to allow mud and contaminants to escape and means are provided for cushioning the engagement of the inserts with the drill pipe to reduce surface damage. Sensing means indicate the grip and ungripped position of the jaws and are used to indicate when a joint or other obstacle prevents the pipe being fully gripped. Also disclosed is a method for floor drive rotary drilling and reaming. The pipe drive bushing may also be used with casing.