I have recently tried 4 fletch on my arrows and I have a mystery . The arrows when shot from my recurve make a loud smack sound when released but when I shoot them from my long bow they are the same as the 3 fletch . The 3 fletch in the curve are just fine . There isn't a thing that could be hitting on the bow and I shoot off from Velcro on both bows . That just don't make sense . I have even tried turning the knocks and that doesn't make a difference .
Must be gremlins .  

Graps....here's where that elevated rest may pay some dividends..?? It will allow a little cleaner flight off the rest...... perhaps a minor change in dynamic spine with the added drag of the 4 fletch??? That longbow has less shelf to clear and relies more on archers paradox to clear the riser. How is the arrowflight from your recurve..??? I love 4 fletch...75-105 degree...

The arrows shoot the same point of impact at 20yds just that smack sound . My long bow has almost as much shelf as the curve and these two bows like the same arrow which is nice . The setup is identical on both bows . I will just use 3 fletch if I hunt with the curve . keep the 4 fletch for the long bow .

sounds like a reasonable solution..