Every line acts differently on the same Spey rod because of the line’s weight and design. Every sink tip alters the cast as does the resistance of every fly. To get the most out of each cast, experiment with the length of the fly line or running line that extends beyond the tip of your fly rod. Try this experiment with a Skagit shooting head: Extend 6 inches of running line beyond the tip then make a cast. Now extend 12 inches and make another cast. Gradually extend the running line in 6 inch increments to determine the most effective length. Also, try this in reverse. Pull in the line until the end of the Skagit head is just outside the tip top and make a cast. Next, pull a couple of inches of fly line inside the tip. Next cast, pull in a couple more inches of fly line, etc. Now you will know what makes the best cast. Every time you change tips, determine this for the new tip. If you put on a new fly, make the appropriate adjustment, especially with large water-logged Intruders, Bunnies and marabou flies. HAPPY CASTING!