The more helical the fletch the quicker the arrow will be stabilized after it leaves the bow and the longer it will remain stable in flight. A long object will not be stable in the air unless there is something providing that stability be it spin or drag. A straight fletch arrow has only drag and very little of it since the fletching is making a straight "slice" through the air. A helical fletch arrow has more drag as well as the benefit of the gyroscopic effect of the spin created by the helical fletch.

When you add wings (broadhead) to the front of the arrow those blades tend to steer the arrow and the fletching has less control over the arrows flight. If the fletching is straight it allows the arrow to veer off course more before the fletching has sufficent drag to straighten out the arrow and overcome the effects of the broadhead. With a helical fletched arrow the fletching always has more control over the arrow than the broadhead does and it is much much harder for the broadhead to steer the arrow off course.



This in an extreme example but you will see the point.

Take an arrow with no fletching and shoot it at 30 yards. It will begin to tumble before it hith the target. Now take an arrow with helical fletch and see how straight it enters the target.


Another test you can do is to take a bow and set it up so that it has a heavy right or left tear in paper. Get someone else to shoot the bow and you watch the arrow go downrange. I will bet you dollars to doughnuts that the helical fletched arrow will recover much faster from the fishtailing than the straight fletched arrow will. You will probably have better groups with the helical fletched arrow than the straight flecthed arrow.