The information that i supplied was wrong for your particular problem, but it was correct for the problem that I described.
Your cause was coming from a different source, but myself and others have encountered the problem of the arrow nocks clipping the edge of the Weaver Rail as the cable sled reaches almost the full draw position. This does not ever occur on the TAC15
's, but it does take place on the TAC15i's.
Glad somebody else on the forum had experience with this problem.