It seem that it is common to cut down an APC electric prop to match a motor battery combination.  For may E-Cavalier I cut down a APC 12x6 EP marked F2B to an 11-1/2 x 6.  In order to get repeatable results I built a fixture to mark the cut off point on the tips.  It amounts to a block of wood a drill bit and a cardboard template.  Photos should explain.