A locking rail mount comprising: a body arranged to be mounted adjacent to a mounting rail , the mounting rail extending in a first direction and including a plurality of ties extending at least partially across the rail in a second direction substantially perpendicular to the first direction; a clamp screw extending through a channel defined by the body and across the mounting rail in the second direction, the clamp screw including a screw head having a first surface facing away from the mounting rail and a second surface facing toward the mounting rail, the second surface including a first plurality of locking elements having a first surface relief geometry; a rail clamp arranged to: i) engage with a first end of a first tie of the plurality of ties to hold the body adjacent to the mounting rail; and ii) disengage from the first end of the first tie of the plurality of ties and release the body from adjacent to the mounting rail; and at least one compression spring positioned between the body and the rail clamp , the at least one compression spring applying a compression force that pushes a first surface of the rail clamp toward the second surface of the screw head, the first surface of the rail clamp including a second plurality of locking elements complementarily arranged with respect to the first plurality of locking elements and having a second surface relief geometry complementary to the first surface relief geometry; wherein, when the clamp screw is tightened, the first plurality of locking elements and second plurality of locking elements are aligned to lock the rail clamp and clamp screw together to prevent unintended rotation of the clamp screw . a body arranged to be mounted adjacent to a mounting rail , the mounting rail extending in a first direction and including a plurality of ties extending at least partially across the rail in a second direction substantially perpendicular to the first direction; a clamp screw extending through a channel defined by the body and across the mounting rail in the second direction, the clamp screw including a screw head having a first surface facing away from the mounting rail and a second surface facing toward the mounting rail, the second surface including a first plurality of locking elements having a first surface relief geometry; a rail clamp arranged to: i) engage with a first end of a first tie of the plurality of ties to hold the body adjacent to the mounting rail; and ii) disengage from the first end of the first tie of the plurality of ties and release the body from adjacent to the mounting rail; and at least one compression spring positioned between the body and the rail clamp , the at least one compression spring applying a compression force that pushes a first surface of the rail clamp toward the second surface of the screw head, the first surface of the rail clamp including a second plurality of locking elements complementarily arranged with respect to the first plurality of locking elements and having a second surface relief geometry complementary to the first surface relief geometry; wherein, when the clamp screw is tightened, the first plurality of locking elements and second plurality of locking elements are aligned to lock the rail clamp and clamp screw together to prevent unintended rotation of the clamp screw . <EOS>