A boom for supporting a drilling and bolting tool includes a first portion, a second portion, an actuator for moving the second portion relative to the first portion in a direction parallel to the longitudinal axis. The second portion includes an elongated shaft having a proximal end and a distal end, the proximal end supported by a shaft support for movement relative to the first portion in a direction parallel to the longitudinal axis, the distal end configured to support the drilling and bolting tool.