Until a rule change is proposed and passed by the board, 4 inch means 4 inch, period. Maybe your bow shoots better with 3 inch ? Maybe your bow shoots faster with 3 inch ? It should ! I know alot of hunters are using shorter fletch now, especially those using expandable broadheads. Does your bow really perform that much better with the 3 inch or are you simply looking to gain more speed ? I would have to say, stick to the rules as they are now and see if they are changed in the future. Kind of the same as the guy who knows the 8X rule for binos but shows up with 10X or 12X because he likes them better ! A definite no-no.