About how many RPM is a fast flip? If full advance is below 300 RPM is it very conceivable that retard is not then being seen, and thus the engine is hard to start?

This may seem like a frivolous question, but I think it is relavent and may encourage a more vigorous flip by hand starters. getting the fingers out of harms way is most important, but the objective is to get the engine started. TIA