Every time I run the. Numbers I come up with just under 6% slip. But that is assuming you are really turning a 28 @ 6100. I have seen some low slip numbers with bravo style herrings but not from a stock bravo 4 blade.

The stamped pitch on stock Bravo 1 props is on the heavy side.
BBlades recommends using 0.7 less than what is stamped.
That gives him right about 4% slip.

I realize that stock bravo props measure slightly less than they are stamped. I just don't see a stock bravo being able to achieve that low of a slip number