A bullpup shotgun which ejects shells from the bottom of its action has a reciprocable cover which, when in a closed position, overlies the breech end of the shotgun's barrel. When in an open position, the cover is in spaced relation to the barrel breech end, allowing access to the shotgun's action to clear an ammunition feed malfunction. The cover is mounted on a butt stock, and the butt stock may be movable relatively to the shotgun's receiver to effect motion of the cover between the open and closed positions.