I ruined two, 16-6 MA props using a drill press. A lot of it was my fault, but this IS something else that can happen when using a drill. I relaxed my pressure on the prop as I was bringing the drill up/out, of the newly drilled hole. It grabbed the prop and it "rode up" the drill bit .... on an angle. This happened last fall when I bought my new engine. I forgot what happened over the winter... and did it again this spring when I bought an extra prop. My bad memory!! I ended up buying a 10-12mm Fox reamer for about $13. ..... the cost of the 2 props I ruined!!......lownslo....