Hi Tim
I have not measured any APC prop for variances in pitch. Usually, I just file the trailing edge a bit to lessen the "Ginsu Knife" effect when flipping.
As MM pointed out, they likely come out of a variety of molds, and the injection material used might be slightly different in consistency as well from batch to batch, and as such may flex differently when running. Actually, I'd just be happy if all the holes were drilled on center! They apparently use a jig of some sort, and still can't get it centered on many of them. For the most part they all run similarly (when the holes are on center), but once in awhile you find one that is a real standout, sometimes you also get a real dud.
After years of using Fiberglass and Carbon props, I find myself favoring the injection molded commercial variety because some of our events require it, but mostly because I'm tired of investing untold hours into hand layup composite props that eventually break. Usually at the most inopportune time.
There may be better props for Clown Racing, but I haven't done any serious testing...
Les