Leading the Target—Swing-Through Method
The two most common methods of leading targets at long distances are swing-through and sustained lead.
Point your shotgun barrel behind the target, moving momentarily to match the target’s speed. Then increase the speed of your gun swing. As the muzzle passes the front of the target, fire and keep moving the barrel at the same increasing speed. In other words, literally "swing through" the target and fire at a blank space in front of the target. Swing-through is the best technique for hunting moving game.