The Collaborative International Dictionary of English v.0.48:
a. & n. from Strike, v.
Striking distance, the distance through which an object can
be reached by striking; the distance at which a force is
effective when directed to a particular object.
(a) The plate against which the latch of a door lock strikes
as the door is closed.
(b) A part of the centering of an arch, which is driven back
to loosen the centering in striking it.