This might seem a silly question...but were they really Parrott's or could they have instead been any one of a variety of approximately 2.9-3.3" rifled pieces? Varying calibers of rifled pieces with various rifling techniques were produced early in the war, particularly in Western foundries of the CSA. Federal Parrotts were rare early on in the TM...which makes CS captures in the Indian Territory difficult to reconcile.