Burl Ives prints "The Rifleman's Song at Bennington" in 1953 and the Folkways recording (1975) both imply the tune is trad but give no attribution. I don't find it elsewhere. Good song - the two smart slaps are rifle cracks, of course & could be clapped or whatever to simulate this. I sing it every August 16th. (Battle of Bennington- 8/16/1777)