The second of A.A. Weinman's Walking Liberty designs. This used to be J1797 in earlier editions of Judd.
Almost a dozen are known including 2 in the Smithsonian which are illustrated below.
For additional information on this and other 1916 half dollars, click here.
Photo courtesy of the National Numismatic Collection of the Smithsonian Institution. The first is inventory 1985.0551.0756, the other 1985.0551.0757.