IMHO, the best solution is to get a 7/16" reamer. These are available from any machine supply store for under $20. I have a 10mm reamer like this that works wonderfully. Drill a 3/8" hole, ream to 10mm and it's perfect. The props that come with the 10mm hole in the center don't seem to have the tolerance that I can get with the reamer. The Bambula's are the worst with (I'm guessing here......haven't measured) around .007 too big of a hole.


-Aaron