ORIGINAL: daven
The OS AX .46 is faster the OS FX .46, well documented in our area as we have been racing those motors for somewhere around 15 years.
Ignore your RPM / PITCH calculations, I won a ton of races using a standard APC 10x7 Sport Prop.
A couple of the APC pylon props do work, I believe many of them are using the 9 1/2'' x 8.5 N (Single N, not double NN).
Good luck.
I don't think the AX has been around 10 years, much less 15.
My experience with both has the FX faster on top end, the AX torquier at lower rpms.