[THEFERMANATOR]

It sometimes happens. Remember, the pitch is the measurement of the blade and how far it should theoretically move with each rotation. Almost all stainless props are also cupped to help the prop bite, and reach that theoretical pitch number. Sometimes a blade is so efficient it runs near 0 slip on it's own, and when you add in a nice deep cup, it adds an extra inch or 2 of pitch to it basically giving you negative slip numbers. Also keep in mind most props are mass produced, and you can see quite a bit of variation from 1 prop to the next. It's not 7ncommon to run 2 or 3 identical props all from the same manufacturer, and all of them turn different rpm, speed, and sometimes different manners.

All's I know was I ran a michigan wheel apollo large diameter 15x17 3 blade prop, and routinely could hit 51 mph gps, at 5700 rpm's verified on my mac digital meter, which came out to -4% prop slip.