With out you giving the serial number, it is after 1907 with the tapered top tang. L.C. Smith stopped making hammer guns in 1932. It is hard to tell from your picture, but after 1917 the only barrels offered were Royal Steel and Grade F in 12 ga. and catalog listed Grade FF as a 10 ga. This FF grade I believe was just a reference for Hunter Arms.
Damascus barrels could be special ordered as well as graded hammer guns. In 1917 this gun cost $22.50.

If you could post the serial number it would help determine year made. It does look like it was used quite often.
It also looks like someone put a center bead on it.

David